Replacing sash windows with upvc. What happens to the job frame?

divadee

We have original Victorian wooden sash windows in our property. Only 3 of them open out of 10. They are an absolute shambles. We also have a massive condensation problem and with this a mould problem on the windows which is horrendous to clean off the paint. We run a dehumidifier 24/7 and it's still bad.

I have come to the conclusion they will need replacing for something which is less maintenance as we do not have any time to repaint the windows at all. We work full time have a young family and it's all we can do to get the cleaning and very very basic jobs done at the moment without trying to strip and fix and paint the windows as well.

We have decided on upvc casement windows fitted with trickle vents. But have wondered how they will fit them. We have cornice surrounds on all the windows and I have googled how upvc is fitted when removing sash windows but not really got anything.

I am concerned that it is going to trash all around the windows and cornice and we will have to redecorate and plaster every single room which we just cannot afford to do.

Can anyone share what has happened if you have changed from wooden sash to upvc casement? In basic terms please lol. I don't understand all the terms connected to sash windows.

I have read some keep the wooden box and put the new window in that but I have also read that's really bad to do. It's so confusing.

divadee

Title should say box frame lol.

ed110220

The main problem I see is if you just remove the windows themselves and leave the wooden lining of the reveal as is, the window surround may still be cold and therefore attract condensation and mould. That's because cold air from outside will get into the sash weight void.

Ideally you'd want to remove that wooden lining, fill the sash weight void with expanding foam or other insulation and refit it or fit new woodwork.

Obviously that's more work and expense though!

societys_child

All the old wooden frames should be removed and the new sash widows along with the new sash uPVC widow frames should be installed directly to the brick surround.


Why would anyone leave old wooden frames in place when fitting new uPVC windows?

divadee

Thanks. So the wooden box frame should be removed. Do you know how much mess and repair work this will take to make good at the end of it?

Society's child - unfortunately we can't afford upvc sash windows. And as this isn't our forever home and it's a block of 4 flats in a converted Victorian house and all the other 3 flats have standard upvc we didn't want the extra expense of the sash windows. I would love to keep the original windows but we have no time and cant afford the expense of the upkeep of them.

societys_child

Ok, the old wood still needs to be removed, and the new uPVC widows installed direct to the brickwork.


A widow installer should be able to give an idea of what it will entail. He'll want to do the job with as little 'mess' as possible.
If it's possible to remove the frames without any plaster falling off, obviously he will.
The uPVC is unlikely be as wide as the wooden frame, and may leave a strip all around the frame that needs filling. Matching uPVC strips with a rounded front edge are available in various widths to cover this and 'make good' meaning re-decoration should not be necessary.

googler

The window fitters, if a company of any size, will send out both a salesman and surveyor to assess the job.

Whenever I/we have had similar jobs done, I've asked both what exactly will be done, where the new will be fitted, how it will butt up to the old, what will be removed, etc.

Talk to your fitters.