Fitting new upvc double glazing onto old wooden sash frames

[Sparkyarnold]

Hi,
I'd really appreciate some advice as searching around I can't seem to find a clear answer.

I'm having my old Victorian sash windows replaced with new upvc double glazed windows shortly through a local green scheme.

What worries me slightly is that the company has said they intend to take out the sashes and fix the new windows into the old wooden frames. They have said that they would replace any rotten wood, but this still sounds like a bit of a bodge job to me.
They've also said that they'll keep the shash boxes where they are, which again I'm not sure if this is ok as I've read in some places that this can result in condensation building up on the boxes and the wood rotting.

I've spoken to the company about my concerns and they said that what they are going to do is standard practice, and as I'm not an expert they might be right, but it's not sitting comfortably with me and I don't have any experience or knowledge to get into a debate with them about it.
Doing some googling, some places say it's fine, others say it's 'cowboy building techniques'.

If anybody could shed their expert opinion light on it I'd really appreciate it.

Thanks

 

[crank39]

It can be done that way but in my opinion it's not the 'done' thing, clearly the installer wants to be in and out with minimum fuss and extra work, personally I would ask them to remove all the boxing and stud it out and plaster board it. Imagine paying all that money for nice efficient PVC windows only for you to carry on losing heat through the hollow box, nah not for me!

Tell them you want it all ripping out and plastered whether it's the right way or the wrong way is irrelevant, your paying and this is how you want it doing!

 

[ronniecabers]

We normally remove the whole window, why leave the box, its reducing the size of the new window too..........

 

[mattice]

perhaps the frames are holding up the brickwork.....

 

[crank39]

That could be a possibility but they should deal with that separately even if its an additional cost to the customer, leaving the box in is just being lazy, probably don't want the mess either.

I've always boxed it out with 2 lengths of 4x2 butted against each other effectively a 4x4 post, screwed the first one into the brickwork and the second onto the first, foam any gaps, fit nice new duraboard, plaster board it out and skim, you then have solid reveals with no voids

So you see its a lot more labour intensive but its the right way and a more professional job, I'd walk away happy knowing that and you'd be happier too

 

[Sparkyarnold]

Hi all,
Thanks so much for your thoughts and expertise.
I'm getting the work done via a green deal type scheme through the council, so am getting the work done at a ridiculously cheap price, and the company are approved by the council to do the work.
It sounds as though because it's through this that the company who said they'd do the job cheapest got the contract and not necessarily the one that'll do the job properly.

Thanks for your thoughts, I think I'll get back on touch with the council and see if they can put pressure on the co. to do the job right and fill the sash boxes in.

Cheers all, I really appreciate your help

 

[crank39]

That explains it, council wants the job doing as cheap as possible and so it goes on down the line