Retrofit- air tightness test

Bowandarrow

Hi

I did a substantial retrofit on a 1970s 3 bed semi d over the past 12 months and am applying for some of the individual seai grants. I had an air tightness test today and it came in at nearly 10.

I'm so disappointed, I took up floors, insulated underneath, internally insulated walls, pumped cavity, attic insulation, new triple glazed windows and doors and still this result- my main concern is the inefficiency of heat pump with a result like this.

3 questions if anyone can give me a steering

1 What is the best method to seal around pipes eg sinks, utility room. Is it expanding foam

2 There seems to be air leaking at ground level where tiles are meeting the external wall... still no skirting board here so what's the best product to use here.

3 my skirting boards on first floor level gaps to the floor. Is it possible to seal and any advice on what to use and how to go about.

Also there seems to be a lot of air between the 2 floors... is this coming from the attic or coming through the walls.. sorry if it's a stupid question

Any help greatly appreciated.

10-10-20

What were the walls pumped with and can you confirm that they were double-leaf cavity and not cavity block? Was the top of the wall sealed before the cavity was pumped, and if so how?

There are airtight expanding foams for use around pipes, have a look in a builder's providers, Passive House from Germany is one brand.

Bowandarrow

Hi.

They were pumped with bead, double leaf cavity. My garage was cavity block which I externally insulated. It is a low tiled roof. I had to pur 3 tiled vents on here and I'm wondering is that part of issue in utility room..

No idea about the top of the wall being sealed... never heard mention of this, should it have been... is it a big job if not.

Thanks I'll check if the local builders has that tomorrow.

Lumen

I prefer the Soudafoam Window & Door product. It comes out of the gun finer than the regular expanding foam products and is easier to use on small holes, even down to old nail holes.

There's lots of encouraging stuff printed on the canister about air tightness, too.

Get a decent gun with a flexible hose attachment, plus some of the PU gun cleaner.

Consider smoke testing.

10-10-20

https://www.boards.ie/discussion/comment/123370587#Comment_123370587

That's the blue foam. Yeah, it's good and remains flexible.

https://www.boards.ie/discussion/comment/123370306#Comment_123370306

For the air-tightness at the first floor, that sounds to me like the porosity of the block as well as the fact that pumped beads aren't airtight. Also were the wall vents fitted with liners (pipe) or were they just holes through both leafs?

Bowandarrow

There's only 1 wall vent in sitting room because of fire place. I've put in mechanical ventilation . ive internally insulated all external walls except garage which I externally insulated.... would this not have kept the air out.. 10 seems poor given I've done so much.

BenIrishHome

I’m just about to retrofit a 25 year old bungalow so following this with interest. One of the major things I’ve recently learned (on boards and elsewhere) is that insulation is overblown and air tightness is where it’s at.

Bungalows are notoriously difficult to air tight, with air blowing thru the eaves and between 2nd floor floorboards etc.

I was quoted nearly €40k for attic insulation and new warm board for the sloped ceilings upstairs, I’m going to spend less than half that and concentrate on air tightness around hatches, new windows and doors etc.

Bowandarrow

I'm devastated I've invested so much money (200k) and getting this result its extremely disappointing. A ber really isn't worth the paper it's written on if hse is running inefficiently. I know prob lots of small areas that can be sealed with expansion foam but im worried the result is so high given the work I've done.

Id definitely recommend the air tightness test to get an understanding g of where the issues are. I got such a surprise yesterday I know i didn't take in sone of what the technician was talking me.🙈

Exiled Rebel

https://www.boards.ie/discussion/comment/123371196#Comment_123371196

It might be worth investing in some professional advice from an airtightness consultant. With an ACH of 10 there's leaks everywhere and potentially big holes which would reduce the score dramatically.

The guy in the link below retrofitted his 1970's bungalow and brought it up to passive standard. Have a look at the posts to see the level of work and detail that needed to be done to get the result he did.

https://www.instagram.com/bungalow_retrofit?igsh=MTRrNTNkMmx4ZDQ3Error

When we built our house I undertook the airtightness myself. An absolute pain in the hoop so it was. The final reading of 1.7 ACH disappointed me as I had spent months researching it and sealing every possible location. I had hoped for a sub 1.0 ACH score.

It's an incredibly frustrating task. Best of luck with it, I hope you manage to get the ACH number down to a level you are happy with.

purplefields

I'm in the process of renovating an old farmhouse with new extension. Just did the whole air-tightness thing.

We didn't use expanding foam. It seemed to be membranes, tape and red, tar like substance (that you do not want to get on your hands or clothes!)

The membrane was installed above the ceiling plasterboard and taped to the walls. Tape was also applied to everything that went through the membrane. The windows were taped inside and outside.

We got all the stuff from promodo in Tralee. (Who also advised what we should get)

Did you do this process?

(Also for grants, everything seems much cheaper without them! Currently doing external wall insulation much cheaper without the grant. Don't get too hung up on the grants. The installers have just increased in the prices)

Bowandarrow

Lots of tape used everyplace. Someone asked earlier was the cavity at top covered and I dont know about this and wonder could that be issue. I will try to check in attic.

What is the best way to seal this if not already done....

monseiur

Unfortunately retrofitting heat pumps is at best 65% successful and is reflected in the eye watering electricity bills that follow unless house is stripped down completely including roof, first floor, ground floor (to fit 100mm underfloor insulation) with option of underfloor heating etc. etc. It would make more economic sense to demolish house, rip up old foundations, pour a new raft and rebuild to ultra modern standard to suit heat pump etc.

It's more economical to upgrade all insulation especially attic, dry line all 'external' walls with 70mm insulated plaster slab, fit triple glazed windows & doors, upgrade all rads and pipework & lagging, if existing oil boiler is past it's sell by date fit a new condensing one. Expect heating cost to drop by at least 30 to 40% if work is done to high quality. Needless to say all suspended timber floors (ground floors) where they exist, would have to be ripped out and replaced with concrete on insulation etc. These suspended floors basically invite draught & cold into the house and are impossible to insulate or draught proof.

Sleeper12

https://www.boards.ie/discussion/comment/123371098#Comment_123371098

Any home with an open fire is unlikely to get good value from a heat pump. Starting point is B value but for savings on your bills compared to gas and oil you really need to be looking at an A energy rating