installation of pvc windows query

eugenedoc1

I have a company installing my windows at the moment.
They have just finished the conservatory today and i went up for a look.
The guy told me that the window sill was a little uneven but not to worry as he would use a grinder and trim about 20 ml off and make it even.
When i went there this evening he has used a thick layer of expanding spray foam all around the bottom of the window frame that meets the sill.
My question is should he not have used some sort of Silicon Mastic Sealant to bond the frame to the sill? Whats the standard practice?
Also i used a Keys**** Lentil and again he has used the spray foam between the poles and frames. Again is this normal practice. Any advise is appreciated

kitser

is the expanding foam visible? it's a bloody nightmare to remove from the frames if they made a mess of it. its ok to use it but surprised that he used it join the poles to the windows. there was probably a cavity between the brick work and the plaster boards so the expanding foam would hold the sill in place, but if it made a mess on the frames make sure they clean it fully before you pay the balance. make sure that the windows lock/unlock with ease, and that the door is working perfectly too.

eugenedoc1

is the expanding foam visible?
Yeah along the bottom connecting with the sill, you can poke your finger through it and make a hole.Around the sides too.
A builder told me they should have set the frames on silicon to make it a complete airtight seal,im spending alot of money on insulation so this looks like a balls of a job.

kitser

sorry. i was thinking about the window board. you're obviously talking about the windows sitting on the external cill. i don't think you have anything to worry about. a good quality silicone would be best to seal the window to the cill if the gap between them is small and the silicone is good. the foam does insulate better and is a sealant, but is not waterproof, but that shouldn't be a problem as the guys will seal the outside. its grand on the wall sides as long as it doesn't affect the function of the windows or doors.

i am assuming that they have yet to plaster the walls and put down the window boards. its a work in progress.

and stop poking holes in the foam.

eugenedoc1

good stuff
Thanks

AlonsoX

kitser wrote: »

sorry. i was thinking about the window board. you're obviously talking about the windows sitting on the external cill. i don't think you have anything to worry about. a good quality silicone would be best to seal the window to the cill if the gap between them is small and the silicone is good. the foam does insulate better and is a sealant, but is not waterproof, but that shouldn't be a problem as the guys will seal the outside. its grand on the wall sides as long as it doesn't affect the function of the windows or doors.

i am assuming that they have yet to plaster the walls and put down the window boards. its a work in progress.

and stop poking holes in the foam.

Once it isnt the finished job its ok, the final seal of sealant will seal it perfectly

Alonso

www.print-cafe.com

enmac

i know nothing about window installation but the overuse of expanding foam seems like a cheap fix
what did installers use prior to expanding foam ?
was there more of an onus on all parties to ensure that the windows were a more snug fit with all cills and surrounds plumb ?
it appears that in general the quality of window installation has deteriorated over the last 10 years with installers doing the job a lot quicker today than they did a few years ago ...

eugenedoc1

Clips attached to windows, windows set into openings,clips fixed to surround with screws. expanding foam sprayed between cill and window

AlonsoX

Once the windows are squared and levelled the expanding foam will hold them in place securely until the final finish is applied (plastered and silicone sealant ) its a bit quicker than drilling holes for brackets but just as secure, the windows wont go anywhere

Alonso

www.print-cafe.com

RKQ

Ensure a good silicon seal to all external joints, especially between the frame and cill. The foam is not waterproof and I've seen wind driven rain travel thru the foam - especially on threshold of upvc doors.:)

AlonsoX

RKQ wrote: »

Ensure a good silicon seal to all external joints, especially between the frame and cill. The foam is not waterproof and I've seen wind driven rain travel thru the foam - especially on threshold of upvc doors.:)

The foam should only be used to hold the frame firm until it is sealed on both sides with silicon and plaster, it shouldnt be used as the sole sealant.
It is very useful for holding it in place and stopping the frame from moving instead of using screws, Finally the silicon and plaster then keeps the window permanently secure. However it shouldnt be used on door frames they need to be screwed to the wall because there is too much movement opening and closing doors

Alonso

www.print-cafe.com