Cavity Wall Insulation

[marty34]

When heating is put off in the house, it gets very cold again very quickly. Been like this since we moved in. It's a detached house and neighbours say the same also.

I presume the builders put cavity wall insulation in when they were building it - sheets I'd say but how could this be checked and even though there is sheet insulation in the cavity, can these walls be also pumped with insulation beads...kind of a top up to fill the gaps etc. between the sheets?
Any help appreciated - need to save a few pound over the winter!!

[Nailer]

Marty, have you any idea how long the house is built, presumably it isn't new build if the heat is rapidly disappearing? You can top up the cavity with silver bead if there is sheet insulation in it. It would be worth drilling a 100mm core hole (in a cupboard or hot press,)in to the inner leaf of the cavity to determine what insulation is in the cavity and what space is left to top it up.
You should also check the insulation thickness in the roofspace, new houses these days have two layers of 200mm thick fibreglass so that could maybe be considered also.

[grounded]

When heating is put off in the house, it gets very cold again very quickly. Been like this since we moved in. It's a detached house and neighbours say the same also.

I presume the builders put cavity wall insulation in when they were building it - sheets I'd say but how could this be checked and even though there is sheet insulation in the cavity, can these walls be also pumped with insulation beads...kind of a top up to fill the gaps etc. between the sheets?
Any help appreciated - need to save a few pound over the winter!!

Answered well above. Maybe also ask a few of your neighbours. If it's an estate a few of them will undoubtedly have the same problem and may have had an insulation company out to check. Some of those insulation companies will do a full survey for you before you have to commit.

[The Subbie]

Drill a hole and have a look or get some fella with a thermal camera
If it's a new house it sounds dodgy
If it's an older house then it will pay in the long run to get the cavities pump with beads etc
Some lads on here had a discussion about the better types a while ago
No point putting up with a cold house, life's too short

[Owen Brannigan]

Heat escapes in a number of ways not just the walls.

By a simple digital hydrometer to measure moisture levels to check for damp. A damp house is harder to heat and loses heat quicker. Even modern houses are damp. If you are regularly above 55% you have a problem. A small smart dehumidifier will solve the problem.

Penetrating damp from rain may be making the house damp and the cold damp walls can be hard to heat and cool houses quickly. Look at damp proofing your bricks or render.

Heat is lost quickly with air movement. Air escapes or enters a houses in many ways, through sockets, poor doors and windows, roof space, etc. An air test will be a simple solution.

If you have wooden floors with a ventilated space below then you are losing serious heat with no insulation and air movement.

Roof space is major source of heat loss which is cheaply remedied with 200mm layers of insulation. Older insulation compacts and loses it value.

Do not go for cavity insulation especially beads as you will end up with the cavity being breached and cold spots which lead to damp, condensation and mould.

If you stop air loss, control the damp and still lose heat then begin a program of dry lining your external walls with plasterboard backed with insulation and foil, moving sockets out and air sealing them. It is dirty and not cheap but effect is instant. You lose a little in room size.

[marty34]

Thanks for the advice guys.  Houses were built around 2006 - height of the boom. I've been chatting to a fee in the estate and they have the same problem.

All double glazed and I topped up the roof insulation a few years ago. No damp in the house.

I've a lad coming out to drill a few random holes and put a camera in to see what the story is.

Owen - do you reckon it's not good to top up insulation sheets (if they're there..lol) with beads?

[Nailer]

Marty, I got the cavities topped up a few years back with silver bead, there was already 40mm sheet material in the cavity, the house was partly rendered externally and partly facing brick and experienced no issues with damp. As someone else mentioned earlier, a survey by a recognised cavity wall insulation co would be a good starting point and see what they recommend.

[marty34]

Marty, I got the cavities topped up a few years back with silver bead, there was already 40mm sheet material in the cavity, the house was partly rendered externally and partly facing brick and experienced no issues with damp. As someone else mentioned earlier, a survey by a recognised cavity wall insulation co would be a good starting point and see what they recommend.

Thanks Nailer - did you notice must difference after you got it topped up with the beads?

[Nailer]

Marty, it made a big difference along with increasing the roofspace insulation by 400mm, the windows were timber double glazed and I eventually replaced them with PVC, I also replaced the front and back door with composite doors complete with frames which helped too. I replaced the gas fire with a wood burning stove which was money well spent  if you have a supply of dry logs.

[grounded]

Thanks for the advice guys.  Houses were built around 2006 - height of the boom. I've been chatting to a fee in the estate and they have the same problem.

All double glazed and I topped up the roof insulation a few years ago. No damp in the house.

I've a lad coming out to drill a few random holes and put a camera in to see what the story is.

Owen - do you reckon it's not good to top up insulation sheets (if they're there..lol) with beads?

What can happen(it happened in a friends house built circa 2005) is that the rigid insulation sheet that was supposed to be attached to the inner leaf had detached in some areas resulting in some cold spots and the inevitable mould forming. He got an insulation company in and I think they either removed or reattached the sheets and subsequently pumped the cavity.

Article here deals with this well
https://www.eco-home-essentials.co.uk/problems-with-cavity-wall-insulation.html

In my previous house built in 90's they had put mineral will in the cavity and I was advised at that time it was not possible to place bead in. I resorted to drylining the inner walls(a dusty, expensive and very disruptive job) but worked brilliantly. Poorly fitted/sealed windows and external doors can also be troublesome. Some good advice earlier with thermal cameras and air tighteness tests. Any money spent will be a very good investment.

[marty34]

Thanks for the advice guys.  Houses were built around 2006 - height of the boom. I've been chatting to a fee in the estate and they have the same problem.

All double glazed and I topped up the roof insulation a few years ago. No damp in the house.

I've a lad coming out to drill a few random holes and put a camera in to see what the story is.

Owen - do you reckon it's not good to top up insulation sheets (if they're there..lol) with beads?

What can happen(it happened in a friends house built circa 2005) is that the rigid insulation sheet that was supposed to be attached to the inner leaf had detached in some areas resulting in some cold spots and the inevitable mould forming. He got an insulation company in and I think they either removed or reattached the sheets and subsequently pumped the cavity.

Article here deals with this well
https://www.eco-home-essentials.co.uk/problems-with-cavity-wall-insulation.html

In my previous house built in 90's they had put mineral will in the cavity and I was advised at that time it was not possible to place bead in. I resorted to drylining the inner walls(a dusty, expensive and very disruptive job) but worked brilliantly. Poorly fitted/sealed windows and external doors can also be troublesome. Some good advice earlier with thermal cameras and air tighteness tests. Any money spent will be a very good investment.

Thanks for that. Yeah, house build about 10 or 11 years ago, so fully doubled glazed (PVC) and I topped up the roofspace.

We light a fire most evenings in the winter but put the heating on for an hour before the kids go to bed.  Don't mind spending a bit as it'll save in the long run as the price of oil is always rising!

I'm getting a company in next week so I'll let yous know how it goes! He's to do an inspection so we'll see after that.