insulating render

[vxsmithers]

Hopefully going to complete on a house next month and the external render is shot. The house is a 1930s detached mock tudor, and is rendered on both sides plus first floor to the front of the house.

So I was thinking of biting the bullet and having some kind of external insulation and then rendered again.

Anyone have any experience of this type of insulation, just thinking that as the house needs to be rendered anyway and its not cavity wall I could save some money in the long run.

so wondered what are the downsides (apart form cost) and life span etc

[B17NNS]

Do you mean the house has no cavity or it is does not currently have cavity wall insulation?

Substantial grants available for the installation of cavity wall and loft insulation. This would be my first upgrade - recently had a 3 bed bungalow done, cavities injected with beads and loft from none to current regs for £350.

Sand and cement is going to end up much cheaper than an insulating render. Compare the costs and work out the payback term. I'm a little dubious of any 10mm thick render doing much to be honest.

[vxsmithers]

should have been clearer - house has solid walls, so if I want to insulate it I either have to lose space inside the house with a stud wall and fill with insulation, or have insulation bolted to the outside of the house with a render applied over the top.

I looked into the grants, but it seems that external insulation is a little too 'new age' to be applicable for grants.

Losing internal space isn't an option for me as I don't want to make the rooms any smaller, but seeing as its detached I want to minimise heat loss. all the companies I've looked at band about the usual spiel of saving £450 a year on heating, but I don't think many people have actually had this done to back up the claims.

I can see in theory how this would work though as you are insulating the brickwork from getting cold, so the brick work retains the heat inside the insulation, rather than keeping the heat from gettin to the walls in the first place.

The advantage seems to be that rather than keeping warm air in a room you are warming the structure, so if you open a door you are not losing the built up heat (to an extent anyway) - prepared to be shot down in flames for my rudimentary physics though!

[mrmaggit]

Go to the Weber website, there is more info on there on insulated rendering than most people will ever need. Finding a quality outfit to install it, is another matter.

[vxsmithers]

mrmaggit said:

Go to the Weber website, there is more info on there on insulated rendering than most people will ever need. Finding a quality outfit to install it, is another matter.

cheers, will have a look

[jas xjr]

This is something I was thinking about today. I was hoping there would some board type of product that I could fix to the external Walls which could then be rendered

[taz turbo]

I used to work in Poland, where it's 'quite' cold come winter. The norm there was to fasten 50mm polystyrene to the outside of the building then a mesh then render over the top. I still have a place out there and had this done, it made a huge difference.

Chris.

[jas xjr]

taz turbo said:

I used to work in Poland, where it's 'quite' cold come winter. The norm there was to fasten 50mm polystyrene to the outside of the building then a mesh then render over the top. I still have a place out there and had this done, it made a huge difference.

Chris.

what do they use to fix the polystyrene? I imagine just a screw and a washer would be ok. Or would it be dot and dab type
of deal?

[TooLateForAName]

The Green Building Forum has a lot of discussions about this.

Several options - if you go for polystyrene use the breathable sort (xps I think - I can never remember which is which xps/eps), hempcrete which you can have sprayed directly onto the walls, fibreboard like pavatex.

Part of the costs come in with needing to modify all the window reveals and the roof/eaves overhang.