Keeping your home warm / heating / energy crisis / insulation etc

Ta - how difficult was it to do, was it ok? That might be the best option for us tbh if that saves the boards.

Yes, we just did it a couple of weeks ago.

What @Sumo said basically, although we used different materials, basically a budget version of this best-practice guide: https://www.ecologicalbuildingsystems.com/post/suspended-timber-floor-insulation-best-practice-installation-guide

Our build-up is (top to bottom):

• Protect Barri-Air Membrane (sits on top of joists and insulation, comes with integrated airtightness tape along one edge, MUCH cheaper than the Pro-Clima stuff) https://insulationmerchant.com/products/protect-barriair-vapour-control-layer-with-integrated-tape-1-5-x-50m

• 150mm Knauff mineral wool insulation (MUCH cheaper than hemp/wood fibre, MUCH easier to install than rigid PIR, vapour-permeable and won't end up with gaps over time as the joists move)

• Standard cheapo roofing membrane (whatever was cheapest in the local builders merchants) wrapped up and over the joists, secured with battens.

All taping done using 'PHS Argo Plus' airtightness tape, using spray-primer when adhering to brick behind skirting boards. This tape is less than half the price of the proper Tescon Vana stuff, and it all adds up as you end up using A LOT of it: https://passivehousesystems.co.uk/product/phs-argo-plus-joining-tape/

The materials cost less than a third of the 'proper' Pro-Clima and hemp bits recommended in the article above, and will be functionally the same.

Be prepared to remove a metric fuckton of rubble/rubbish from your floor voids; ours took up three full skips and cost a fortune in labour to shift. Took much longer to delete the mountains of rubble than it did to actually install the insulation.

Also, sadly less than 20% of our nice original Victorian floorboards were salvageable; most of them splintered into dust whilst trying to carefully remove. Shout out to @Fox for saving the day with local spares.

I've got quite a bit of the Barri-Air membrane left over if you want it.

Not hard as such but crawling in the 2 foot gap under the floor wasn't exactly fun and I never want to do it again. You also need a good flow of someone cutting the PIR to the right sizes then feeding them down to the person doing the fitting. The actual fitting is a bit of a pig because old joists are not perfectly parallel and using sticky expanding foam to fill gaps will ruin clothes/hair.

As a bonus, here's what it looks like without the floor boards as we were replacing that whole area and this is how claustrophobic it is.

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You're lucky that your voids were clear enough to crawl through! The rubble in ours was literally touching the floorboards...

We did end up paying someone to fill, sand and Osmo the floor after though, looks & feels much nicer than before so took the edge off losing the original floorboards.

Yeah it was alright actually. A few spiders but mostly just old wiring. The previous owners had installed a couple of strip lights under there but of course we'd ripped out the old wires from the consumer unit by then so they didn't work. They'd run some audio cables from a cd player in the kitchen speakers around the ground floor and telephone wires so each room had a socket so at some point it was cared for.

Thanks! I have also read that guide as it goes, good to know if you've done it and the hints on cheaper stuff are really helpful.

Just trying to work out if we pull them all up and gamble on saving the boards (when we pulled out 2msq of boards in an en suite room upstairs they all came out intact, but maybe that's easier as they were shorter boards?) or try to add insulation from underneath (+ good to know @Sumo managed it so it is doable).

Will give you a DM on the membrane if we go ahead, trying to come up with our plan asap cheers!

Also how come you needed to excavate so much stuff if you were pulling the boards - was there just insufficient space for air circulation etc underneath?

Yeah doesn't look loads of fun, but I'm not too claustrophobic so wouldn't rule out giving it a go if that's the best option! Choices choices

We did it, but from below and used mineral wool held in place with netting. We plan on putting a membrane on top after our new heating system goes in as all new pipe work will fuck all of it. I don’t think I could have managed PIR from underneath. Mineral wool was ok though.

It's always best to have a completely clear subfloor void with plenty of unobstructed air-bricks for ventilation. As mentioned, ours were all filled to the brim with shite, all air-bricks blocked.

Yeah makes sense, if it was that full under there I'd do the same. I don't think it is that bad, based on peering through the one loose "access" floorboard we have in the hall, so the crawl method is probably open to me (whether I should be happy about that or not is another question)

Pretty easy job really, I did my ground floor room by room. Agreed that rubble clearing was the time consuming bit. Lift boards, remove rubble, replace/treat bad timber, insulate (I used 200mm PIR), fill gaps, add membrane, new sub floor (mine's OSB), final floor (parquet). I doubt ground floor floorboards would ever be particularly salvageable unless your house has always been bone dry, 50% of mine turned to dust too.

Unfortunately there's always a chance you discover new issues to solve at the same time (bad ventilation, broken hearths, bad electric, etc).

anyone got advice for insulating and making airtight window reveals? Getting rooms replastered w/ new windows and want to make sure we get it right

Is it just a case of

Fixing the windows in place as normal
Sealing externally with airtightness tape + render etc
Stuffing behind reveals with loose insulation
Fitting insulated plasterboard around the reveal
Finish with timber as normal

Am I missing anything?

"Fitting insulated plasterboard around the reveal”
just be aware of the thermal changes in that area and sealing properly to avoid any interstitial condensation. I would use spray foam adhesive and ensure a continuous bead to enclose any areas behind. Legally you may need fixings but you can use less with foam than dot/dab, this is because it’s a fire risk with the boards falling off the wall and blocking escape.
If you are removing the window boards then a good look at the cavity closer to see if it’s worth fitting it properly and a modern version? all depends on the age and construction of your building.

thanks - is the spray foam adhesive instead of internal airtightness tape?

No, for fixing the insulated plasterboard.

Have you got cavity closers?

When I get my windows replaced I'll be fitting those.

i'm in a solid wall edwardian place so suspect it doesn't apply?

Has anyone used recessed lighting hoods? I want them for the 'outshot' part of the house on the ground floor where the ceiling has external roof above it. I like these - https://www.thermahood.com/

The problem is I don't have access from above without going in through the roof which I don't want to do, and I can't fit them from below without making a mess of the ceiling.

Has anyone encountered this problem?

Asking in here because people seem to be a bit more knowledgeable; we were away the last week.

On the Octopus app, Saturday usage was showing about what I'd expect for daily residual use (~20p/0.9 kWh), but Monday to Friday were all double that (45p/1.9 kWh).

Just wondering what might have caused it

i used some for the roof to cover recessed bathroom lighting so the insulation went over the top they are pretty straight forward really just a fire resistant cap that goes over the fitting . Not sure how you would fit without going in to the roof though as they are fairly deep and wide.

as you say the mess from going from underneath. cut a smallish access hatch. ?

Anyone have any recommendations for trades to fit insulation - both under floorboards and also probably loft?

Even what type of tradesperson does that would be helpful for me

Our builders just did our underfloor insulation, and did a good job. DM me if you’d like their details; East based.

Ta - should probably have said I'm SE so depends how mobile they feel, but worth a shot!