Airtightness Retrofit

Alkers

We have a 1950s 3-bed terraced house and are working through energy efficiency upgrades.

We have updated heating controls, changed to an efficient combi boiler, installed humidity controlled ventilation, LED lights etc.

We are planning new windows and external wall insulation in March / april of next year and that is probably as far as we will go with this house.

One item that we haven't investigated / addressed at all is air tightness. I see plenty of people online offering to do air tightness surveys and the like for €400+. I understand these will give the house an overall scoring but will they identify particular leaks / areas of concern? Once/if these are identified, what's involved in addressing them? I haven't really seen anyone advertising these works (other than the surveys).

The house is solid block construction but there is a suspended timber floor. Is it worth investigating air tightness before progressing with windows and EWI? There are gaps between the floorboards in places which I'd imagine are worth having sealed before we put down carpet etc? Other areas have laminate flooring on top of the floorboards - is it necessary / worthwhile lifting this? What else is achievable when not planning any other major works?

Calahonda52

From here
https://www.boards.ie/vbulletin/showthread.php?t=2058029821
.
so what is the red brick: is it a faux cavity?
.
Floor needs to be insulated.
.
https://www.nsai.ie/about/news/publication-of-sr-542014-code-of-practice
.
plus loads of threads on it both here and in DIY

Alkers

We haven't actually cored through the brick to check but I suspect it's pretty much cladding. You can see the front elevation here:

We have cored in all the other rooms (for vents) and it was solid block.

Re: the floor insulation, as you can imagine this would involve substantial disruption, particularly where most of the house is in good decorative order. Hence it not being so appetising! I will do some more reading on it.

MicktheMan

OP, you absolutely should have the house tested for airtightness before spend big on ewi & new windows etc. If you don't there is a high likelihood of not getting the full benefit of your other works.

Calahonda52

will u get PP for EWI on front?.
for the floors but down an A/T layer and seal t wall behind skirting board if possible

Alkers

Calahonda52 wrote: »

will u get PP for EWI on front?.
for the floors but down an A/T layer and seal t wall behind skirting board if possible

I don't think we need it, not listed buildings and the houses in the terrace are all different. If needed we can get the ewi to resemble the current situation.

What would you use as the at layer? Does this go beneath the existing floorboards or could we put it above it and beneath new floor coverings?

Calahonda52

Alkers wrote: »

I don't think we need it, not listed buildings and the houses in the terrace are all different. If needed we can get the ewi to resemble the current situation.

What would you use as the at layer? Does this go beneath the existing floorboards or could we put it above it and beneath new floor coverings?

1. I would be checking re the EWI and PP
it will also be very tricky with the bay windows up against the soffit board
.
2. as you don't want to have any disruption over the boards will do.

listermint

Looking at the front elevation you may examine bringing the windows out to meet the insulation.

Two reasons.

1. Your bays would currently be behind the insulation layer covering the side windows if the layer was say 100mm eps. And I gather that won't work asthetically or from a functional perspective.

2. Bringing windows out to meet EPS is the best method to eliminate cold bridging as much as possible.

Not fun work I did this myself boxing windows out by 100 mm beyond the building envelope. I used 200mm EPS. I also had a bay window but in my case bay was single story but required me to build a new bay roof. Old one was rotten anyway.

Alkers

listermint wrote: »

Looking at the front elevation you may examine bringing the windows out to meet the insulation.

Two reasons.

1. Your bays would currently be behind the insulation layer covering the side windows if the layer was say 100mm eps. And I gather that won't work asthetically or from a functional perspective.

2. Bringing windows out to meet EPS is the best method to eliminate cold bridging as much as possible.

Not fun work I did this myself boxing windows out by 100 mm beyond the building envelope. I used 200mm EPS. I also had a bay window but in my case bay was single story but required me to build a new bay roof. Old one was rotten anyway.

We will be replacing windows at the same time so will be moving them, thanks.

Alkers

Calahonda52 wrote: »

1. I would be checking re the EWI and PP
it will also be very tricky with the bay windows up against the soffit board
.
2. as you don't want to have any disruption over the boards will do.

What issue do you see with planning?

From looking around the area, none of the houses (not all exactly like ours) that have it have applied.

Do you have a recommendation for the AT layer? Is there something specific to floors I should use? Google isn't being helpful!

Calahonda52

Alkers wrote: »

What issue do you see with planning?

From looking around the area, none of the houses (not all exactly like ours) that have it have applied.

Do you have a recommendation for the AT layer? Is there something specific to floors I should use? Google isn't being helpful!

OK so if there is a precedent for it already in the estate then grand.
Call
https://www.ecologicalbuildingshop.ie
or
https://www.partel.ie
or look here
https://www.dupont.com/building/all-products.html
who make Tyvek, which is one of the original makers of this stuff

BryanF

Go on an air-tightness course day course

Gumbo

BryanF wrote: »

Go on an air-tightness course day course

Saint Gobain do them for free in their Technical Academy.
Highly recommended.