Reducing energy bills

pangolin

Interested to hear rjsterry's thoughts on best steps to insulate our house (and shirley_basso's).

Ours was built in around 1904-1906. Looks quite like this (although it's not this one)



Things I know it could do with:

• Front wall has a bit of a bulge, not moved in years as it has been re tied but, I guess, could do with coming down and going up again properly (perhaps with insulation this time?)
  
• Rear wall has no insulation either, but no compelling reason to take it apart
  
• Most of the ground floor is suspended timber floor over about a 1 foot cavity, then dirt under that, all uninsulated
  
• The kitchen area, for some reason, is on a concrete slab
  
• There's a little utility extension that is lino floor on bare concrete, single skin, little bit of insulation in the roof, absolutely freezing in winter
  
• Loft has a reasonable layer of insulation, surveyor did say we should add a few more inches
  
• Odd patches of damp around near the floors. Not sure if dpc has failed in places, or it's where things like french doors have been added and bridged gaps, or what
  
• Also on the damp, the air bricks are right at ground level at the back, and ever so slightly below it out front. Thanks to whoever built the pavement up!
  

Probably more...

Really if we were staying for years there is lots I would do. Probably take down the outer leaf on the front and insulate it at the same time. Knock down the extension and get a 'proper' one across the whole width of the back, insulate back wall at the same time. Sort out the floors, etc. However we're probably only be here for another year (possibly move this year, although doesn't feel like a hugely wise time to get a bigger mortgage). So, any quick wins?

shirley_basso

Weve got an 'in need of modernisation' bay fronted Victorian terrace.

Like yours, suspended timber floors (1/2 rooms carpeted, hallways also bare) but also a concrete kitchen.

Windows and roof extremely drafty. Need to insulate loft, do curtains then think bang for buck. Were here for 10y or so, so happy to spend more money when it comes available subject to inflation.

Pross

RJS is obviously best placed on this but one thing (that you've already thought of) is that cavities are there for a reason and insulating could cause problems with damp.

Not sure how much benefit insulating a suspended floor would give you and the risk of that against making damp worse (although I believe there are insulating materials that can actually help with damp).

How are the doors and windows? I've noticed lately that in our house the curtains are moving in a draught coming through the double glazing so think we may need to get them replaced soon.

We have two things that I think are really badly affecting our energy use. The first is the conservatory especially as the door to it from the dining room is always open. That is an easy and obvious fix. The second is the converted single skin, flat roofed garage where I spend most of my day working and which is heated by oil filled electric radiators. Short of demolishing it and building a proper extension I'm not sure how we can resolve that one. I should have gone for the free solar panels when they were offered to us.

rjsterry

pangolin said:

Interested to hear rjsterry's thoughts on best steps to insulate our house (and shirley_basso's).

Ours was built in around 1904-1906. Looks quite like this (although it's not this one)



Things I know it could do with:

• Front wall has a bit of a bulge, not moved in years as it has been re tied but, I guess, could do with coming down and going up again properly (perhaps with insulation this time?)
  
• Rear wall has no insulation either, but no compelling reason to take it apart
  
• Most of the ground floor is suspended timber floor over about a 1 foot cavity, then dirt under that, all uninsulated
  
• The kitchen area, for some reason, is on a concrete slab
  
• There's a little utility extension that is lino floor on bare concrete, single skin, little bit of insulation in the roof, absolutely freezing in winter
  
• Loft has a reasonable layer of insulation, surveyor did say we should add a few more inches
  
• Odd patches of damp around near the floors. Not sure if dpc has failed in places, or it's where things like french doors have been added and bridged gaps, or what
  
• Also on the damp, the air bricks are right at ground level at the back, and ever so slightly below it out front. Thanks to whoever built the pavement up!
  

Probably more...

Really if we were staying for years there is lots I would do. Probably take down the outer leaf on the front and insulate it at the same time. Knock down the extension and get a 'proper' one across the whole width of the back, insulate back wall at the same time. Sort out the floors, etc. However we're probably only be here for another year (possibly move this year, although doesn't feel like a hugely wise time to get a bigger mortgage). So, any quick wins?

Golden rule is 'fabric first'. Sounds like the roof is reasonably insulated already but should at least be 6" deep and better 8". Be careful to maintain ventilation of the roof as insulating the ceiling will make the loft colder and so if not well ventilated will get condensation and then mould growth. Watch out for insulation blocking any ventilation routes.
Your walls will be tricky to insulate but you may be able to install blown cavity insulation into the cavity. Don't worry about a wobble in the wall unless there is ongoing movement.

With an uninsulated suspended floor the air flow beneath the floor can cause a lot of heat loss, especially if you have open chimneys pulling the unheated air through the gaps in the floorboards. Also have a look at windows and doors to see if there are any big draughty gaps. There is a balance to be struck as if the house is too airtight you will get poor air quality and mould growth where humid air meets colder parts of the structure. You want controlled ventilation rather than draughts.
The other area to look at is the kitchen (common for kitchens to have solid floors in Edwardian properties - not quite sure why) and particularly the utility room. If solid walls, you can insulate internally or externally. The latter is probably easier.

As regards damp, it's important to get to the bottom of what is causing it there are quite a few possibilities and different solutions for each.

You are in the right bit of the world as there is an organisation called the Green Register based in Bristol that provides courses on among other things bringing old buildings up to modern energy use standards. It's mostly aimed at building professionals, but they may be able to put you in touch with some local people who know what they are doing.

All that said, if you are only going to be there for another year, I would save your money for the next house. By the time you have planned and executed the work you will only have a few months to enjoy it.

laurentian

rjsterry said:

pangolin said:

Interested to hear rjsterry's thoughts on best steps to insulate our house (and shirley_basso's).

Ours was built in around 1904-1906. Looks quite like this (although it's not this one)



Things I know it could do with:

• Front wall has a bit of a bulge, not moved in years as it has been re tied but, I guess, could do with coming down and going up again properly (perhaps with insulation this time?)
  
• Rear wall has no insulation either, but no compelling reason to take it apart
  
• Most of the ground floor is suspended timber floor over about a 1 foot cavity, then dirt under that, all uninsulated
  
• The kitchen area, for some reason, is on a concrete slab
  
• There's a little utility extension that is lino floor on bare concrete, single skin, little bit of insulation in the roof, absolutely freezing in winter
  
• Loft has a reasonable layer of insulation, surveyor did say we should add a few more inches
  
• Odd patches of damp around near the floors. Not sure if dpc has failed in places, or it's where things like french doors have been added and bridged gaps, or what
  
• Also on the damp, the air bricks are right at ground level at the back, and ever so slightly below it out front. Thanks to whoever built the pavement up!
  

Probably more...

Really if we were staying for years there is lots I would do. Probably take down the outer leaf on the front and insulate it at the same time. Knock down the extension and get a 'proper' one across the whole width of the back, insulate back wall at the same time. Sort out the floors, etc. However we're probably only be here for another year (possibly move this year, although doesn't feel like a hugely wise time to get a bigger mortgage). So, any quick wins?

Golden rule is 'fabric first'. Sounds like the roof is reasonably insulated already but should at least be 6" deep and better 8". Be careful to maintain ventilation of the roof as insulating the ceiling will make the loft colder and so if not well ventilated will get condensation and then mould growth. Watch out for insulation blocking any ventilation routes.

Apologies for jumping in here Pangolin but RJS seems to know what he's talking about and so I'd like to ask a question if I may.

We live in a mid 70's detached house. It's been extended a few times and the extended bits that we have done have been insulated in line with Building Regs - we have also had cavity wall insulation in all of the walls.

However, our loft space is, for all intents and purposes, not insulated. On the surface of it, clearing the loft out and laying some rolls of fibreglass insulation (or anything else that could be suggested) between the joists seems something that even I could do but I believe there are aspects that need to be paid attention. In terms of ventilation, it looks like the only place this is apparent is the "finishing gap" (or lack of it!) where the roof joists meet the eave. Would it be just a case of esuring that this remains by keeping the vertical "face" of the insulation (and any riser boards needed) in line with the current base of the loft?

Secondly, there is a flat roof extension over the original garage with no apparent access to the cavity between roof and ceiling. I can just about see that there is some token fibreglass laid over the ceiling but the insulation needs improving - any ideas?

Apologies for the hijack again Pangolin!

photonic69

We live in a typical late Victorian terrace and have tried our best to insulate to save fuel/money.

I echo what is suggested above. The things that made the biggest difference in order:

• Loft Insualtion - as much as you can get up there and right to the eaves but leave space for ventilation.
  
• Windows and Doors - replace any single glazed and or draughty windows with new double glazed units. Makes a huge difference.
  
• Replace old central heating radiators with modern ones. Much more efficient and heats the rooms more quickly. Also place insulated foil behind the rads to stop heat going into the walls.
  
• Doors - I installed door brushes along the bottom to prevent draughts.
  
• Suspended wooden floors - we have stripped floorboards and rugs. It was always cold downstairs. A few years ago I insulated underneath them with rockwool held in place with a plastic mesh stapled to the bottom of the joists. Luckily we have a 3ft crawl space under the boards. It wasn't easy. It was filthy, messy, hard work lying on your back getting the stuff in place and stapling the mesh. Took about 3 days of what was continuous ab crunches. Got most of a 6 pack at the end. It no longer feels cold around your ankles in the evenings.
  
• Chimneys - we don't have open fires but still have a hearth and chimney. I boarded one up with ply and a mesh vent to allow some ventillation. The other I made a chimney sheep out of woollen underlay and some ply and wedged that in place. Made a big difference.
  
• Put woollen underlay under your rugs. Makes them spongy and warm to walk on.
  
• Kitchen - we have a concrete floor. It used to have vinyl tiles when we bought the house. It was very cold to walk on. I put down a laminate flooring with 6mm insulation boards underneath and it is not longer cold to walk on.
  
• Keep doors to rooms closed as this helps to keep the heat in and not leak out into the colder hallways.
  
• Curtains - heavy curtains or close fitted fabric blinds work well.
  

Hope that list helps? I've still another 2 windows and the back door to get replaced this year. I think every bit of energy saving is going to be required in the foreseeable future!

rjsterry

laurentian said:

rjsterry said:

pangolin said:

Interested to hear rjsterry's thoughts on best steps to insulate our house (and shirley_basso's).

Ours was built in around 1904-1906. Looks quite like this (although it's not this one)



Things I know it could do with:

• Front wall has a bit of a bulge, not moved in years as it has been re tied but, I guess, could do with coming down and going up again properly (perhaps with insulation this time?)
  
• Rear wall has no insulation either, but no compelling reason to take it apart
  
• Most of the ground floor is suspended timber floor over about a 1 foot cavity, then dirt under that, all uninsulated
  
• The kitchen area, for some reason, is on a concrete slab
  
• There's a little utility extension that is lino floor on bare concrete, single skin, little bit of insulation in the roof, absolutely freezing in winter
  
• Loft has a reasonable layer of insulation, surveyor did say we should add a few more inches
  
• Odd patches of damp around near the floors. Not sure if dpc has failed in places, or it's where things like french doors have been added and bridged gaps, or what
  
• Also on the damp, the air bricks are right at ground level at the back, and ever so slightly below it out front. Thanks to whoever built the pavement up!
  

Probably more...

Really if we were staying for years there is lots I would do. Probably take down the outer leaf on the front and insulate it at the same time. Knock down the extension and get a 'proper' one across the whole width of the back, insulate back wall at the same time. Sort out the floors, etc. However we're probably only be here for another year (possibly move this year, although doesn't feel like a hugely wise time to get a bigger mortgage). So, any quick wins?

Golden rule is 'fabric first'. Sounds like the roof is reasonably insulated already but should at least be 6" deep and better 8". Be careful to maintain ventilation of the roof as insulating the ceiling will make the loft colder and so if not well ventilated will get condensation and then mould growth. Watch out for insulation blocking any ventilation routes.

Apologies for jumping in here Pangolin but RJS seems to know what he's talking about and so I'd like to ask a question if I may.

We live in a mid 70's detached house. It's been extended a few times and the extended bits that we have done have been insulated in line with Building Regs - we have also had cavity wall insulation in all of the walls.

However, our loft space is, for all intents and purposes, not insulated. On the surface of it, clearing the loft out and laying some rolls of fibreglass insulation (or anything else that could be suggested) between the joists seems something that even I could do but I believe there are aspects that need to be paid attention. In terms of ventilation, it looks like the only place this is apparent is the "finishing gap" (or lack of it!) where the roof joists meet the eave. Would it be just a case of esuring that this remains by keeping the vertical "face" of the insulation (and any riser boards needed) in line with the current base of the loft?

Secondly, there is a flat roof extension over the original garage with no apparent access to the cavity between roof and ceiling. I can just about see that there is some token fibreglass laid over the ceiling but the insulation needs improving - any ideas?

Apologies for the hijack again Pangolin!

Yes, maintaining ventilation in the loft space is important. Roofs tend to be ventilated through the eaves and you've correctly identified that it is easy to block this route by stuffing insulation into the corner of the loft. You can get corrugated plastic rafter trays that tuck in between the underside of the roof and the insulation to maintain an air gap.

https://klober.co.uk/ventilation/eaves/p/roll-out-rafter-tray

Or you can fit tile vents over the surface of the roof to replace the blocked route to the eaves.

Ideally you want the cavity wall insulation to meet the loft insulation to form a continuous line, but this is sometimes difficult to achieve, particularly if the roof is shallow pitched. This may be where you need more specific advice to avoid a 'cold bridge' in the strip of uninsulated roof.

pangolin

laurentian said:

rjsterry said:

pangolin said:

Interested to hear rjsterry's thoughts on best steps to insulate our house (and shirley_basso's).

Ours was built in around 1904-1906. Looks quite like this (although it's not this one)



Things I know it could do with:

• Front wall has a bit of a bulge, not moved in years as it has been re tied but, I guess, could do with coming down and going up again properly (perhaps with insulation this time?)
  
• Rear wall has no insulation either, but no compelling reason to take it apart
  
• Most of the ground floor is suspended timber floor over about a 1 foot cavity, then dirt under that, all uninsulated
  
• The kitchen area, for some reason, is on a concrete slab
  
• There's a little utility extension that is lino floor on bare concrete, single skin, little bit of insulation in the roof, absolutely freezing in winter
  
• Loft has a reasonable layer of insulation, surveyor did say we should add a few more inches
  
• Odd patches of damp around near the floors. Not sure if dpc has failed in places, or it's where things like french doors have been added and bridged gaps, or what
  
• Also on the damp, the air bricks are right at ground level at the back, and ever so slightly below it out front. Thanks to whoever built the pavement up!
  

Probably more...

Really if we were staying for years there is lots I would do. Probably take down the outer leaf on the front and insulate it at the same time. Knock down the extension and get a 'proper' one across the whole width of the back, insulate back wall at the same time. Sort out the floors, etc. However we're probably only be here for another year (possibly move this year, although doesn't feel like a hugely wise time to get a bigger mortgage). So, any quick wins?

Golden rule is 'fabric first'. Sounds like the roof is reasonably insulated already but should at least be 6" deep and better 8". Be careful to maintain ventilation of the roof as insulating the ceiling will make the loft colder and so if not well ventilated will get condensation and then mould growth. Watch out for insulation blocking any ventilation routes.

Apologies for jumping in here Pangolin but RJS seems to know what he's talking about and so I'd like to ask a question if I may.

We live in a mid 70's detached house. It's been extended a few times and the extended bits that we have done have been insulated in line with Building Regs - we have also had cavity wall insulation in all of the walls.

However, our loft space is, for all intents and purposes, not insulated. On the surface of it, clearing the loft out and laying some rolls of fibreglass insulation (or anything else that could be suggested) between the joists seems something that even I could do but I believe there are aspects that need to be paid attention. In terms of ventilation, it looks like the only place this is apparent is the "finishing gap" (or lack of it!) where the roof joists meet the eave. Would it be just a case of esuring that this remains by keeping the vertical "face" of the insulation (and any riser boards needed) in line with the current base of the loft?

Secondly, there is a flat roof extension over the original garage with no apparent access to the cavity between roof and ceiling. I can just about see that there is some token fibreglass laid over the ceiling but the insulation needs improving - any ideas?

Apologies for the hijack again Pangolin!

No please carry on, It's a topic I'm sure lots of people will have questions / answers on.

rjsterry

photonic69 said:

We live in a typical late Victorian terrace and have tried our best to insulate to save fuel/money.

I echo what is suggested above. The things that made the biggest difference in order:

• Loft Insualtion - as much as you can get up there and right to the eaves but leave space for ventilation.
  
• Windows and Doors - replace any single glazed and or draughty windows with new double glazed units. Makes a huge difference.
  
• Replace old central heating radiators with modern ones. Much more efficient and heats the rooms more quickly. Also place insulated foil behind the rads to stop heat going into the walls.
  
• Doors - I installed door brushes along the bottom to prevent draughts.
  
• Suspended wooden floors - we have stripped floorboards and rugs. It was always cold downstairs. A few years ago I insulated underneath them with rockwool held in place with a plastic mesh stapled to the bottom of the joists. Luckily we have a 3ft crawl space under the boards. It wasn't easy. It was filthy, messy, hard work lying on your back getting the stuff in place and stapling the mesh. Took about 3 days of what was continuous ab crunches. Got most of a 6 pack at the end. It no longer feels cold around your ankles in the evenings.
  
• Chimneys - we don't have open fires but still have a hearth and chimney. I boarded one up with ply and a mesh vent to allow some ventillation. The other I made a chimney sheep out of woollen underlay and some ply and wedged that in place. Made a big difference.
  
• Put woollen underlay under your rugs. Makes them spongy and warm to walk on.
  
• Kitchen - we have a concrete floor. It used to have vinyl tiles when we bought the house. It was very cold to walk on. I put down a laminate flooring with 6mm insulation boards underneath and it is not longer cold to walk on.
  
• Keep doors to rooms closed as this helps to keep the heat in and not leak out into the colder hallways.
  
• Curtains - heavy curtains or close fitted fabric blinds work well.
  

Hope that list helps? I've still another 2 windows and the back door to get replaced this year. I think every bit of energy saving is going to be required in the foreseeable future!

All good stuff. Just keep an eye on background ventilation to make sure you don't get poor air quality (AQ) . Relative humidity (RH) should ideally be around 50% and is a reasonable proxy for overall AQ.

pangolin

rjsterry said:

laurentian said:

rjsterry said:

pangolin said:

Interested to hear rjsterry's thoughts on best steps to insulate our house (and shirley_basso's).

Ours was built in around 1904-1906. Looks quite like this (although it's not this one)



Things I know it could do with:

• Front wall has a bit of a bulge, not moved in years as it has been re tied but, I guess, could do with coming down and going up again properly (perhaps with insulation this time?)
  
• Rear wall has no insulation either, but no compelling reason to take it apart
  
• Most of the ground floor is suspended timber floor over about a 1 foot cavity, then dirt under that, all uninsulated
  
• The kitchen area, for some reason, is on a concrete slab
  
• There's a little utility extension that is lino floor on bare concrete, single skin, little bit of insulation in the roof, absolutely freezing in winter
  
• Loft has a reasonable layer of insulation, surveyor did say we should add a few more inches
  
• Odd patches of damp around near the floors. Not sure if dpc has failed in places, or it's where things like french doors have been added and bridged gaps, or what
  
• Also on the damp, the air bricks are right at ground level at the back, and ever so slightly below it out front. Thanks to whoever built the pavement up!
  

Probably more...

Really if we were staying for years there is lots I would do. Probably take down the outer leaf on the front and insulate it at the same time. Knock down the extension and get a 'proper' one across the whole width of the back, insulate back wall at the same time. Sort out the floors, etc. However we're probably only be here for another year (possibly move this year, although doesn't feel like a hugely wise time to get a bigger mortgage). So, any quick wins?

Golden rule is 'fabric first'. Sounds like the roof is reasonably insulated already but should at least be 6" deep and better 8". Be careful to maintain ventilation of the roof as insulating the ceiling will make the loft colder and so if not well ventilated will get condensation and then mould growth. Watch out for insulation blocking any ventilation routes.

Apologies for jumping in here Pangolin but RJS seems to know what he's talking about and so I'd like to ask a question if I may.

We live in a mid 70's detached house. It's been extended a few times and the extended bits that we have done have been insulated in line with Building Regs - we have also had cavity wall insulation in all of the walls.

However, our loft space is, for all intents and purposes, not insulated. On the surface of it, clearing the loft out and laying some rolls of fibreglass insulation (or anything else that could be suggested) between the joists seems something that even I could do but I believe there are aspects that need to be paid attention. In terms of ventilation, it looks like the only place this is apparent is the "finishing gap" (or lack of it!) where the roof joists meet the eave. Would it be just a case of esuring that this remains by keeping the vertical "face" of the insulation (and any riser boards needed) in line with the current base of the loft?

Secondly, there is a flat roof extension over the original garage with no apparent access to the cavity between roof and ceiling. I can just about see that there is some token fibreglass laid over the ceiling but the insulation needs improving - any ideas?

Apologies for the hijack again Pangolin!

Yes, maintaining ventilation in the loft space is important. Roofs tend to be ventilated through the eaves and you've correctly identified that it is easy to block this route by stuffing insulation into the corner of the loft. You can get corrugated plastic rafter trays that tuck in between the underside of the roof and the insulation to maintain an air gap.

https://klober.co.uk/ventilation/eaves/p/roll-out-rafter-tray

Or you can fit tile vents over the surface of the roof to replace the blocked route to the eaves.

Ideally you want the cavity wall insulation to meet the loft insulation to form a continuous line, but this is sometimes difficult to achieve, particularly if the roof is shallow pitched. This may be where you need more specific advice to avoid a 'cold bridge' in the strip of uninsulated roof.

Think I need to bite the bullet and sort out the loft as the first quick win.

When I looked into this before I saw these recommended - is it worth installing a few of these rjsterry?

https://www.lbsbmonline.co.uk/manthorpe-felt-lap-vent?

pangolin

The rafter trays look like something you put on over the rafters, under the felt etc. How do you do that if your roof is already on?

laurentian

pangolin said:

The rafter trays look like something you put on over the rafters, under the felt etc. How do you do that if your roof is already on?

I have this question too!

rjsterry

pangolin said:

rjsterry said:

laurentian said:

rjsterry said:

pangolin said:

Interested to hear rjsterry's thoughts on best steps to insulate our house (and shirley_basso's).

Ours was built in around 1904-1906. Looks quite like this (although it's not this one)



Things I know it could do with:

• Front wall has a bit of a bulge, not moved in years as it has been re tied but, I guess, could do with coming down and going up again properly (perhaps with insulation this time?)
  
• Rear wall has no insulation either, but no compelling reason to take it apart
  
• Most of the ground floor is suspended timber floor over about a 1 foot cavity, then dirt under that, all uninsulated
  
• The kitchen area, for some reason, is on a concrete slab
  
• There's a little utility extension that is lino floor on bare concrete, single skin, little bit of insulation in the roof, absolutely freezing in winter
  
• Loft has a reasonable layer of insulation, surveyor did say we should add a few more inches
  
• Odd patches of damp around near the floors. Not sure if dpc has failed in places, or it's where things like french doors have been added and bridged gaps, or what
  
• Also on the damp, the air bricks are right at ground level at the back, and ever so slightly below it out front. Thanks to whoever built the pavement up!
  

Probably more...

Really if we were staying for years there is lots I would do. Probably take down the outer leaf on the front and insulate it at the same time. Knock down the extension and get a 'proper' one across the whole width of the back, insulate back wall at the same time. Sort out the floors, etc. However we're probably only be here for another year (possibly move this year, although doesn't feel like a hugely wise time to get a bigger mortgage). So, any quick wins?

Golden rule is 'fabric first'. Sounds like the roof is reasonably insulated already but should at least be 6" deep and better 8". Be careful to maintain ventilation of the roof as insulating the ceiling will make the loft colder and so if not well ventilated will get condensation and then mould growth. Watch out for insulation blocking any ventilation routes.

Apologies for jumping in here Pangolin but RJS seems to know what he's talking about and so I'd like to ask a question if I may.

We live in a mid 70's detached house. It's been extended a few times and the extended bits that we have done have been insulated in line with Building Regs - we have also had cavity wall insulation in all of the walls.

However, our loft space is, for all intents and purposes, not insulated. On the surface of it, clearing the loft out and laying some rolls of fibreglass insulation (or anything else that could be suggested) between the joists seems something that even I could do but I believe there are aspects that need to be paid attention. In terms of ventilation, it looks like the only place this is apparent is the "finishing gap" (or lack of it!) where the roof joists meet the eave. Would it be just a case of esuring that this remains by keeping the vertical "face" of the insulation (and any riser boards needed) in line with the current base of the loft?

Secondly, there is a flat roof extension over the original garage with no apparent access to the cavity between roof and ceiling. I can just about see that there is some token fibreglass laid over the ceiling but the insulation needs improving - any ideas?

Apologies for the hijack again Pangolin!

Yes, maintaining ventilation in the loft space is important. Roofs tend to be ventilated through the eaves and you've correctly identified that it is easy to block this route by stuffing insulation into the corner of the loft. You can get corrugated plastic rafter trays that tuck in between the underside of the roof and the insulation to maintain an air gap.

https://klober.co.uk/ventilation/eaves/p/roll-out-rafter-tray

Or you can fit tile vents over the surface of the roof to replace the blocked route to the eaves.

Ideally you want the cavity wall insulation to meet the loft insulation to form a continuous line, but this is sometimes difficult to achieve, particularly if the roof is shallow pitched. This may be where you need more specific advice to avoid a 'cold bridge' in the strip of uninsulated roof.

Think I need to bite the bullet and sort out the loft as the first quick win.

When I looked into this before I saw these recommended - is it worth installing a few of these rjsterry?

https://www.lbsbmonline.co.uk/manthorpe-felt-lap-vent?

I think that does the same job as the rafter tray, so yes.

rjsterry

laurentian said:

pangolin said:

The rafter trays look like something you put on over the rafters, under the felt etc. How do you do that if your roof is already on?

I have this question too!

You are correct, however, you can also retrofit these internally. You would need to cut into sections and fit between each pair of rafters. Or use the product laurentian found.

photonic69

When I was doing my MIL loft space I bought some of this to help vent the roof space when the insulation went up the the eaves. However it was impossible to reach in far enough as the pitch of the roof was too shallow and I simply could not get it to work as intended. I just rolled the thing up into a tube and shoved a couple between each rafter spacing.





https://www.bpdstore.co.uk/glidevale-ev600-rafter-ventilator/p/144

laurentian

rjsterry said:

laurentian said:

pangolin said:

The rafter trays look like something you put on over the rafters, under the felt etc. How do you do that if your roof is already on?

I have this question too!

You are correct, however, you can also retrofit these internally. You would need to cut into sections and fit between each pair of rafters. Or use the product laurentian found.

The felt lap vent looks like a very easy thing to fit - thanks for the heads up.

Any suggestions as to a suitably thick (270mm?) insulation roll?

rjsterry

laurentian said:

rjsterry said:

laurentian said:

pangolin said:

The rafter trays look like something you put on over the rafters, under the felt etc. How do you do that if your roof is already on?

I have this question too!

You are correct, however, you can also retrofit these internally. You would need to cut into sections and fit between each pair of rafters. Or use the product laurentian found.

The felt lap vent looks like a very easy thing to fit - thanks for the heads up.

Any suggestions as to a suitably thick (270mm?) insulation roll?

Sounds good. Main limitation will be size of loft hatch.

rjsterry

photonic69 said:

When I was doing my MIL loft space I bought some of this to help vent the roof space when the insulation went up the the eaves. However it was impossible to reach in far enough as the pitch of the roof was too shallow and I simply could not get it to work as intended. I just rolled the thing up into a tube and shoved a couple between each rafter spacing.





https://www.bpdstore.co.uk/glidevale-ev600-rafter-ventilator/p/144

Worth considering the overall state of the roof and whether you can combine a few jobs to make scaffolding worth it.

pangolin

Regarding damp, any tips for how I go about identifying the cause without taking too much of the house apart?

At the rear downstairs for example, there is a patch that seems to appear when it rains, either side of the french doors.

There are 3 air bricks nearby, which I've made sure are clear as best I can.

The floor inside is some kind of engineered wood floor over suspended timber, so not trivial to take up and poke around.

rjsterry

Do you have any photos? Inside and outside.

pangolin

Added a little arrow where the faint water mark is, not very dark at the moment as it's not been too wet.

Suspect the cat flap is not helping matters on the other side? Maybe things need repointing. I guess the dpc is the big question mark, not sure how I would know if that's an issue.

rjsterry

Two possible routes for water ingress that I can see: at the edge of the door frame and where the pointing has come away.
The air brick looks fine. I would suggest sealing that joint at the edge of the door frame with some exterior grade mastic (rake out any old or decayed stuff first) and making good the missing pointing. I'm not sure anyone wants a page on repointing, but the mix should be weaker than the surrounding brickwork.

briantrumpet

Won't be long before this turns into the RJS subscription channel...

johngti

225% increase in my energy bills from April. Could turn out to be an important thread…

johngti

Sorry, 125%.

morstar

I’m well in credit and contract runs till June. I’ve worked out what it should be at cap from April so if they try something silly I’ll be a bit miffed. Heard of colleagues with similar huge rises and larger.

rjsterry

briantrumpet said:

Won't be long before this turns into the RJS subscription channel...

😱

pangolin

rjsterry said:

Two possible routes for water ingress that I can see: at the edge of the door frame and where the pointing has come away.

The air brick looks fine. I would suggest sealing that joint at the edge of the door frame with some exterior grade mastic (rake out any old or decayed stuff first) and making good the missing pointing. I'm not sure anyone wants a page on repointing, but the mix should be weaker than the surrounding brickwork.

Thanks. Searching on eg screwfix brings up silicone, is this ok?

https://www.screwfix.com/p/no-nonsense-builders-silicone-grey-310ml/912GR?tc=HT5&ds_kid=92700058168037379&ds_rl=1249416

Is it worth looking into lime mortar, or just going for a higher ratio of sand to cement?

veronese68

I think I'm going to have to rip up the floorboards and insulate under them 🙄 sounds very tedious.
We are in a Victorian semi, similar issues to many above. Loft is well insulated and we have double glazing, but solid brick walls are not good.
A friend down the road had the side of their place rendered with an insulating render. But the render is ugly and the brickwork looks so much better.

briantrumpet

rjsterry said:

briantrumpet said:

Won't be long before this turns into the RJS subscription channel...

😱

How many posts can we view for free, before the Cakestop Pro © software kicks in?

pangolin

veronese68 said:

I think I'm going to have to rip up the floorboards and insulate under them 🙄 sounds very tedious.
We are in a Victorian semi, similar issues to many above. Loft is well insulated and we have double glazing, but solid brick walls are not good.
A friend down the road had the side of their place rendered with an insulating render. But the render is ugly and the brickwork looks so much better.

Have a look at some videos by this chap, but yeah looks tedious...

https://youtu.be/vwKJ7tmMbiQ