Insulating my house help

Just wanting to check I’m on the right lines with this please…

We have a 60s chalet style house, upstairs is in the roof and is barely insulated so it’s cold in winter and boiling in summer.

I can get access reasonably well in to the eaves and I’m thinking of putting 50mm kingspan in behind the plasterboard in between the stud work, which I hope should make a decent difference. At the moment there are a few random tatty bits of fibreglass draped over various bits.

I’m just doing our bedroom at the moment as we’re about to re-decorate but will do the whole upstairs over time.

The end wall I will board over using the plasterboard with insulation attached as I’d rather not rip it all out and we can lose 60mm off the length of the room without worrying.

The floor is also an issue as when it’s windy it takes all the heat out of it by blowing through between the floor and the ceiling below. Can I block the ends up to stop the draught? I see no issue with this as the ends of the joists in the eaves will still be open and allowed to breath, between floor and ceiling is all internal.

Cheers for any help 🙂

I would speak to a professional as there are three factors to consider when insulating an existing building: heat retention, damp protection/ventilation and air tightness – if you do one without the others it can lead to problems with damp e.g. blocking air bricks.

My mum’s house was just like that. I would go for a plasterboard/insulation laminate that includes a vapour barrier. Can’t see a problem with closing the gaps between the floor joists, the ends will still be ventilated as you say. FWIW.

I’m in a similar construction.

Blocked the ends of the floor joists. Made a big  difference. To floor temperature

I insulated the back of the vertical walls in the bedrooms  with glass wool then went over that with superfoil multilayer to provide a vapor and wind barrier…. The eaves venting made the insulation largely pointless without the continuous layer –  I then bubble foiled the back of the trusses. Leaving an air path up and over the roof space.

My slanty bits I put in 50mm kingspan to allow for airflow between the sarkin and the kingspan It’s less than ideal but I have so much airflow due to wind I can live.

I partitioned off 1/4 of my attic space and insulated it (leaving an air gap up and over ) and in there heated by my inverter I have my solar batteries.

The biggest thing I did was change the 1980s wooden double glazing for modern vika framed uPVC with modern glass.

Would advise if you can stretch to or borrow….a FLIR camera. I’ve got one for my phone and it highlights non visible/non obvious cold bridges well.

Similar discussions here with a builder, pretty much all you have listed. Be aware when maxing out insulation check you are heating the house optimally, so new trvs all round and uprated rads. Also, if you can get access underneath insulate underfloor like your loft.

Thanks, looks like my plan isn’t terrible then.

Ideally I will speak to someone and hopefully get them to do it but might end up doing it myself depending on availability.

This was supposed to be a quick paint to refresh the room, it’s grown arms & legs already!

Thanks, looks like my plan isn’t terrible then.

It’ll be a PITA job though. Floor up, work around ground floor wiring and plumbing that runs in the ceiling/floor void

Insulate the pipes while you’re there and consider a waterproof insulation throughout in case of leaks

Our local library lends out FLIR cameras

i should also add to my previous post – in light of the reduction in living space ventilation (drafts) i fitted a PIV.

It’ll be a PITA job though.

Yes, I fully expect it to be shit to do. Which is probably why I haven’t done it sooner!

The next step is to do under the downstairs floor, which will also be terrible.

So having crawled about behind my walls I think I’ll get much better coverage with insulated board on top of the original.

I’ll lose 100mm all round but it’s a big enough room that I’ll get away with it.

Inside a wardrobe the slanted bit of ceiling close to the roof I’ll do 50mm on the outside and 50mm plasterboard on the inside, I don’t think I’ll get with 100mm and still be able to hang stuff in the cupboard.

And the sides of the dormer will have to be the same.

It’ll be much quicker and less mess to fit from the inside.

I see fitting guides that recommend foam adhesive and a few mechanical fixings.

A ton of insulated plasterboard ordered. Hopefully I’ll get started next week 😮

I then bubble foiled the back of the trusses. Leaving an air path up and over the roof space.

So you’ve effectively got a roof that’s now double skinned, say 150mm away from the original roof? I think you mean that any venting to the outside world is in-between the roof and your new layer?

That would be a massive job looking at the state of mine and the soffit boards underneath are so leaky that they probably need replacing before I try and stop the wind getting through. I think blocking up between floor and ceiling will make a big difference.

then went over that with superfoil multilayer to provide a vapor and wind barrier….

This seems like a good idea too and shouldn’t be too arduous.