Fixing windows in tightly and properly secured window fittings

Troy McClure

We havn't decided on which window company. One thing that worries me is the quality of installation by some large window manufacturers. Someone told me today to get whoever we choose to use EPDM Tape around the window to give it a good seal before they use the expanding foam.
Has anyone done this? or anyone have any tips on ensuring windows/doors fit and seal well.?

Also. We were looking at Munsters Future proof window. It looks a big and solid window. Only thing is there is no metal reinforcement within the frame. And yes I know this is to get the U value down. However I seen other window makes with metal but with foam to counteract this problem. there the handles and hinges can be screwed into metal to give them a solid footing. If there is no metal, in such a heavy window as above do people think screwing parts into just the upvc will hold over time??

Thanks

martinn123

A window not reinforced, with metal, and expanding foam, avoid, in my opinion.
The foam if too much used will warp the window, as it expands, and lead to all sorts of problems.

Try using Fixing Straps, these are metal straps which are screwed into the outside of the frame, and then screwed into the wall to give a secure fix, use plenty on all four sides of the frame.

I agree with your comment on the hinges, handles etc fixed to a non reinforced frame, makes sense as the screws are just held by the PVC, much stronger fix into metal. A large side hung sash, with screws held by PVC, will not last.

Finally with regard to your choice of supplier, have a look at the thread below, on MJ moved to consumer issues, also do a search for MJ, a few threads in DIY, you should read.

Troy McClure

The window would be fixed in using metal straps. I never heard that using too much expanding foam can warp windows ovedr time.

One of the mods posted in another thread that no metal within the frame is common now to get U value down for companies. Is this an genuine issue with such windows?

martinn123

If you are using the fixing straps it should be OK. What I have seen, is where expanding foam is used, on its own, as it expands it can warp the frame of the window where its not reinforced. ( not a recomended way to fit windows, but lots of fitters use this method )
If you think about it, say at the top, there is a concrete head which will not move, so as the foam expands it has to push against something, and as the frame is PVC without a metal reinforcing it will bend.
The straps should keep it level, and the foam should just expand outwards, to be cleaned off later.

With regard to improving the U value, by not having metal, this may be the case, but as you have mentioned, the drawback on a larger frame, is that the hinges, are just screwed into PVC, and will they take the weight over time.

braftery

ALL windows must be fitted using metal straps !!

There are EN norms for installation of windows and doors, and they were written for a reason.

Most uPVC profiles require a metal strengthener inside them once the frames get beyond a certain dimension and or weight. Using 3G glass packages will usually mean that this requirement comes sooner.

As far as I am aware there is only one uPVC profile that does not require steel .. this is a new profile GENEO from the Plastics company REHAU. This profile has a carbon fibre core which gives the profile itself the rigidity.

Martinn is correct about the possibility of expanding foam pushing on frames, it can also happen on timber doors if they do not have adequate fixings around the frame.

However expanding foam is the best material to use for installing windows as it bridges the insulation layer right out to the edge of the window. To not fill this gap with foam is like having your window permanently open.

Use the right type of expanding foam, there is alot of crap on the market and there are specific types for window and door installation.

Waterproof expanding tapes can be used, but their uses are more specific and for certain installation applications only (eg: windows being placed up against stone facade that is already in place.)

EDPM seals are usually only used in window to window joints as they have no expanding qualities and need to be compressed to function properly.

A well installed 2G window will keep you warmer than a badly installed 3G one. You are the only Building Control your job will ever see in this country !! Dont let your project be the next Priory Hall !

gears

braftery wrote: »

As far as I am aware there is only one uPVC profile that does not require steel .. this is a new profile GENEO from the Plastics company REHAU.

There's another one I've heard of from the company Profile 22 where they use a composite for their support