un insulated bay window.

spongybobby

Dont understand what the builder was thinking when they installed the bay window in my house. It was done before i owned the house so its up to me to sort the problem.

Basically the bottom of the bay window is un insulated and is causing condensation to form on the wood as its warm inside and cold outside.


I would like the underside of the bay to look nice.. So was thinking to use foam board to insulate the bottom, but no idea what to use to clad it with.

Would be very interested in what suggestions can be made here as im sure i cant be the first to suffer this.

Furts

WBP, exterior, faced plywood. Then decorate it - this could be more durable and quicker if you avoid the spruce, cheaper plywoods.

SailorSam

Are you putting the foan on the inside ?
Just cover it with plasterboard and decorate. Id get some secondary double glazing to do the bay. You can DIY.

A_Frayed_Knot

Once plasterboard is up or whatever you use, have a look at wallrock thermal liner insulation, may be just what you are looking for.

I came across this by accident, when looking for thick lining paper to cover polystyrene paper I used to cover the inside of the outside walls, then needed a thick lining paper to cover it. Used wallrock - perfect for me.

spongybobby

I may have not described myself too well in my first post.

If i look at my bay window from outside the house, the wall has a hole where the bay is, there is a peice of roughly 25mm thick wood ( its nice wood , not shure what though) then the double glazing windows sit on top of the wood, the top of the bay has a good sloped roof on it and is flashed correctly.

Its the wood that concerns me, the wood is the only insulator between outside and inside for say 50cm out of the house by 1.8m width.

What i want to do is put some foamboard insulation on the bottom (outside) of the wood then box the foam in to hide it and make it weather proof..
Thing is, the bay is on the side of the house that gets direct rain, so whatever material i use to box / protect the foam it must be water proof...

I.e not plasterboard etc

chappers

What is the bay made of is it brickwork or timber frame, cavity or single skin.
If you add extra insulation to the outside, what is going to happen to the drips on the window sill.
Any reason you can't insulate from the inside, use insulated plasterboard and then fit new internal window sills. Insulating the inside is probably going to be the most efficient.

spongybobby

I will have to add some pictures when i get home today.

I cant insulate the inside as any height added on the inside will then impede on the window airflow things.
And the height would then impede on the actual upvc frame of the window.

If i insulate the outside of the bay then i wont see it from inside.

This image isnt of my house but its similar in the construction of the bay which is more important.
http://duratechindia.com/wp-content/uploads/2015/04/Bay-windows.jpg
As you can see there is no insulation directly underneath the sill on the bay.. This is where i want to insulate.

vic_sf49

A link to a property with a similar set up....

http://www.rightmove.co.uk/property-for-sale/property-51695656.html?premiumA=true

In my case I have a white plastic windowsill, and underneath (outside) is wood. I don't know if there's anything between those layers, but if there is, it's not doing a good job of retaining heat.

My idea was to put a layer of insulation on it, underneath and on the outside, and then a layer of something that would be more weatherproof. I was thinking of the thin silver stuff (thermawarp or equivalent), then cover with some waterproofing fabric then a layer of wood.

If it was going to protrude below the base of the windowsill, I'd just make sure the front has a trim on it, or a decent piece of wood I could paint / varnish.

spongybobby

Vic. Yes very similar to that.

Main issue is is making sure its air tight or as close as possible to air tight, any air that can get between the insulation and wood of the bay or brick of the house may cause issues down the line.

I would use a decent foam really as im not sure that thin thermawrap will provide enough insulation

vic_sf49

If I get sick of wiping the window, I might get rid of the bay altogether. Annoyance factor vs cost argument going on in my head.

I'm also going to quiz the neighbours, to see if they've done anything to solve the problem.

tonyh66

vic_sf49 wrote: »

If I get sick of wiping the window, I might get rid of the bay altogether. Annoyance factor vs cost argument going on in my head.

I'm also going to quiz the neighbours, to see if they've done anything to solve the problem.

Can't understand the designers head when they put these bay type windows into a normal opening without creating the extra floorspace
under it. You could I suppose get a bricky to build a wall under it and fill the newly created void with rockwool.