UKC

I've just had my old wooden bathroom window replaced with a uPVC one whilst I was at work this morning. The fitter has lined the new window up with the inner cavity wall leaving the cavity and outer wall exposed to the elements. I appreciate that the quote excluded redecoation etc., but I would have expected the window to fit up against the outer rendering rather than the inner. Am I right, or is it good practise to have the window set further in? There is a sill attached to the window so there's no worry about water ingress down the cavity in front of it, but now I'm going to have to block the cavity either side of the window (kingspan?) and render the outside in it's current state. Surely it's best to have the window in the outer skin? Answers by Monday so I can get on the blower if necessary first thing!

In reply to Toerag: Assuming it is a straight replacement, I would expect the new window to be where the old one was!

In reply to Toerag:

It should be fitted to the outer skin of a cavity wall and sealed with silicone. If the gap between the inner skin and the pvc frame is too big for a bead of silicone on the inside then they should fit a pvc strip around the reveals which butts up to the window frame covering the gap. If you're redecorating then don't bother with the pvc strip, just fill and make good.
And don't let them tell you any different!
(I spent a couple of years fitting windows and aluminium curtain walling for some of the UK's largest window companies when the joinery was a bit scarce)

In reply to Toerag:

It should be in the outer skin of the building so it needs moving.

In reply to Toerag: there must have been some quite considerable size difference between the thickness of old and new for that to happen. I did my bathroom window the other week, did it myself, well, with a mate helping. Went like a dream, ok the old glass unit had been mastic'd in and we had to smash it to get the glass out but hey, once the old hardwood frame was out the new fitted like a glove with 5mm gap all round. I packed it with cardbard to hold in position and foamed it all around and went for a brew. When the foam had gone off, sliced off the excess, 2 frame fixers either side and mastic'd up, looks great! Ordered online, choose style and enter sizes and choose glass. £180 delivered, took about 10 days to arrive.
http://www.windowforce.co.uk/

In reply to Toerag: window should line through on the outer cavity, as far forward as possible to minimise external redecoration. Certainly cavity should not be exposed, this will lead to water ingress, even if the cill covers the bottom. Head and reveal exposed.

Reference the internal redecoration; it is reasonable to expect the window fitter to use 75mm trim to cover the cavity at the head, jambs and cill. You'd be responsible for additional making good, but I'd be alarmed if the fitter made a lot of mess.

I'd also check what fixings he's used and at what centres. Sometimes it's necessary to use a strap back to fix into the internal cavity - for a variety of reasons - so fixing through the frame isn't always necessary.

Should use expanding foam if there are any gaps greater than 15-20mm rather than just silicone.

Personally I wouldn't except the level of workmanship from what you've described, all basic stuff. I'd be shocked to find a tradesman carrying out work to that standard. i.e. alarm bells

In reply to blanchie14c:

Not really. Typical double glazed uPVC windows usually are around 70mm thick depending on manufacturer. Unusual to be >100mm unless triple or enhanced standard glazing.

Typical cavity size is usually 50-100mm and bricks are just over 100mm wide. So inside edge to outside edge is roughly 250-300mm thick (assuming brick-brick not brick-block cavity and not including for internal or external decoration).

So there is no way the frame size should be greater than the external skin. If the window couldn't have been direct fixed through frame for some reason, then it should have been strapped back.

In reply to Toerag: Could you post a pic?

In reply to Toerag:

The window unit should typically close the cavity ie part on both the inner and outer leaf.
I would expect the unit to be fixed to the inner leaf with steel straps in a position which allows a bead of silicon to seal the very small gap between the unit and the outer skin of masonry.

You shouldn't be expected to do any external work and most replacement windows I've seen go in have also be fitted with timber or PVC facia surrounds which limit the amount of internal redecoration required.

Your job sounds a bit shoddy.

http://www.imiweb.org/design_tools/masonry_details/details/01.030.0502.php

In reply to Toerag: I owned a large double glazing business for 11 years & have never heard of a window being intentionally fitted in this way; I can think of absolutely no reason for it or benefit; indeed as already stated it is actually quite harmful to your property.
Modern windows are usually fitted flush with the inside edge of the outer skin if the property is block/cav/block, or slightly back if its brick. On older properties the (timber) window was used to seal the cavity. I would normally expect an installer to simply replicate what was there - this doesn't sound like the case in your property. Did you get given an installation specification? (For example we used to offer a range of finishes, plastering, PVC trim, timber line, leave for others etc etc) Either way you have a reasonable expectation of best practise and this is not.

In reply to Toerag:

What?!!!! That's nuts. Get him back to fit it properly!!!!

In reply to Toerag:

>> We have just had three wooden double glazed windows replaced by PVC ones. All the new windows are deeper, more space between the two panes of glass to conform to latest standards. They have been put into where the original windows were, i.e. recessed three centimeters back from the outer face of the outer wall.

In reply to Toerag: I thought as much! I'll try to post pics later for your amusement, but the wall is concrete block skins (we don't do bricks in Guernsey due to the island being granite) with a wide handjam-sized cavity between. I checked the quote and it did say it included 'to make good' but not 'redecorating' - the guy hasn't even made good! I'll be on the blower first thing Monday morning....

In reply to Toerag: Phoned them up yesterday morning, got home after work and it had been refitted in the outer leaf . Didn't really have to get too shitty with them, just said I was disappointed and it wasn't really best practise! I think the fitter simply did what was most convenient for him when he had the afternoon off.