Cavity wall insulation around window - questionable building work....

Brain$torm

Hello,

I'm looking for some advice. I am currently having a new bathroom fitted and the builder kept going on about getting a new window too. He said that's what everyone does. Anyway, after ripping out the old tiles, he exposed the mineral wool insulation that I had professionally installed, many years ago (pumped in). It came right up to the windows edge (the upvc frame) all the way around - still looking as good as new, despite it being 15 years old. He tells me it's 'crap', and without asking or telling me, he scrapes out about 10-20 cm of it, all around the cavity and throws it away. He then replaces it with broken pieces of polystyrene from a box, as well as an old piece of loft insulation, saying this is much better. I challenged him on it, buying some proper mineral wool rolls, asking him to replace it. He refused, shouted and said don't interfere with the job, as he knows what he's doing. He's now stuck plasterboard all around the window, almost touching it. Thus, I cannot remove the stuff he put around it, without somehow getting the plasterboard off too. I think he was planning to fill the rest of the cavity around the window with expanding foam.

Now, I'm no builder, but I do know that you have to be very careful with putting insulation into cavity walls and you should use the proper stuff. He's also leaving a gap between floorboards too, telling me he's happy wih it and I shouldn't interfere. I mean, it's my house!! I'm thinking I need to get the plasterboard off and get that stuff out, before the tiles go on...

Any advice would be much appreciated.

Cheers.

grumbler

10-20 cm of insulation on the sides? That's too much as window frame usually isn't that wide.
Anyway, personally I don't trust UK cowboys with anything. And, IMO, the correct way of doing this is with insulated plasterboard and small gaps filled with mineral wool if needed.. 

stuart45

Hard to be sure without seeing the job. The cavity would normally be closed at the reveals by either returning the inside blockwork or using cavity closers.
Cavity insulation batts are designed to keep out moisture.

Section62

Brain$torm said:

I'm looking for some advice. I am currently having a new bathroom fitted and the builder kept going on about getting a new window too. He said that's what everyone does.

Can you clarify whether the window has now been replaced, and if so who did the work?  If the builder replaced the window then is he FENSA (or otherwise) approved, and if not, has he talked to you about getting building regs certification?

Replacing the window either requires building control certification, or the installer to be a member of an approved scheme.

That he's using polystyrene packaging (which typically is flammable, with toxic fumes) would suggest he isn't competent to do this work, and ideally should be stopped (before his work results in someones death).

Brain$torm

Here are some pictures of the window:  You can see some tiny pieces of mineral wool left and he pieces of polystyrene he's put there.  The old piece of loft insulation has been stuff in, at the top.  The bottom cavity across the window has got tons of the broken polystyrene in.  It sent alarm bells off in my head, when I saw it, but didn't know what to do.  It's the first major renovation I've ever had done! It hasn't been a nice first experience.  All the walls have now been plasterboarded, so the stuff cannot be removed easily.  It's properly stuck down to the bricks.  He hasn't fitted a new window yet and I am not going to get one either.  I know about FENSA and he is not certified.  He also told me I didn't need trickle vents, but I know about the new regs, saying that you likely do.

He has said he wont tile up to the window yet, so I can get a new one fitted without damaging them.  I am not getting one though. There's been a few alarm bells with him.

Brain$torm

Section62 said:

Brain$torm said:

I'm looking for some advice. I am currently having a new bathroom fitted and the builder kept going on about getting a new window too. He said that's what everyone does.

Can you clarify whether the window has now been replaced, and if so who did the work?  If the builder replaced the window then is he FENSA (or otherwise) approved, and if not, has he talked to you about getting building regs certification?

Replacing the window either requires building control certification, or the installer to be a member of an approved scheme.

That he's using polystyrene packaging (which typically is flammable, with toxic fumes) would suggest he isn't competent to do this work, and ideally should be stopped (before his work results in someones death).

No.  The old window is still there.

Brain$torm

stuart45 said:

Hard to be sure without seeing the job. The cavity would normally be closed at the reveals by either returning the inside blockwork or using cavity closers.
Cavity insulation batts are designed to keep out moisture.

Please see pictures above and below.  I did buy some cavity wall rock wool, but he refused to use it, and said the polystyrene was better.

Brain$torm

Here's what it looks like now:

stuart45

The job does look a mess. The original window probably sat further back across the cavity, behind the face brickwork. There's not much you can do without removing the plasterboard. The inner reveals don't line  up equally each side of the window.

Brain$torm

stuart45 said:

The job does look a mess. The original window probably sat further back across the cavity, behind the face brickwork. There's not much you can do without removing the plasterboard. The inner reveals don't line  up equally each side of the window.

The window hasn't been replaced, it's still where it was originally.  It's a,n old house. All he's done around the window is remove the mineral wool insulation, replaced it with polystyrene packaging (and a bit of expanding foam), and put the plasterboard up.  I don't even know what a reveal is. 

Do you mean just the plasterboard around the window, or all the walls?

stuart45

What I meant was the original timber window when the house was first built would have sat further back. The inner reveal is the vertical part of the wall next to the window.
The plasterboard around the window is a mess.