External over Internal Insulation

firebird84

About 6 years ago we moved into our completely uninsulated, and therefore very cold house. At the time we didn't have a lot of cash for renovations so with the help of some knowledgeable friends we installed some internal insulation in the master bedroom (it being the coldest room in the house), it's worked out pretty well in the interim.

Fast forward to now and we are considering getting external insulation wrapped around the entire house as, bar the master, the house is still very cold on bad winter days. Would it going to cause any major issues to put external insulation up on walls that are already insulated from the inside?

My longer term plan would be to take it out of the bedroom as it would be no longer needed and get the space back but we've a baby on the way and need to prioritise timewise on any work we get done so it likely wouldn't happen for at least a year after the external stuff goes up.

Dudda

No problem with anything you're suggesting. I'd recommend looking at 150mm or even 200mm external insulation. You can get a grant and therefore 99% of external insulation I see put on existing building is 100mm to qualify for the grant. The cost between 100mm and 150mm is tiny as most of the cost is in the labour, scaffolding, plastering it after, etc.

firebird84

Cheers I'll look into that! We were also considering the airtightness test that I've seen a lot of people recommend in other insulation threads here but the house was built in 1976 so I'm not sure how much it would solve vs insulation. Quite a few others in our neighborhood have gone the same route and seem satisfied.

listermint

Id be getting minimum of 150mm , I went with 200mm myself . Self install as the quotes I was getting were outlandish however my house is fairly large and the spec i wanted was up to top of block and down below ground level and they were quoting with gusto for that.

Including grant it simply was a non runner for me.

But I would recommend it and also attic insulation is a must at the same time.

Do everything with a view to airtightness standard too but don't be anal about it. Tapes etc were necessary and so on

firebird84

listermint wrote: »

Id be getting minimum of 150mm , I went with 200mm myself . Self install as the quotes I was getting were outlandish however my house is fairly large and the spec i wanted was up to top of block and down below ground level and they were quoting with gusto for that.

Including grant it simply was a non runner for me.

But I would recommend it and also attic insulation is a must at the same time.

Do everything with a view to airtightness standard too but don't be anal about it. Tapes etc were necessary and so on

Yeah I definitely want to add some more attic insulation at the same time but we might try do that ourselves, self install for external would be beyond my capabilities!

How easy is it to do much of the airtightness fixes DIY? That side of it is more new to me.

listermint

firebird84 wrote: »

Yeah I definitely want to add some more attic insulation at the same time but we might try do that ourselves, self install for external would be beyond my capabilities!

How easy is it to do much of the airtightness fixes DIY? That side of it is more new to me.

Mostly finding the gaps and filling them with filler and or tapes . The usually spots around windows and doors are the most common but you can get problem's with poorly fitted plasterboard.

Draughts can be found with a lit incense stick and note then down on a piece of paper. Draw them out and then come back later to repair and check off.