To crack or not to crack.?

[Makeitstop]

Hi all,

All opinions welcome on this.

I'm renovating a house which has had to have a number of windows replaced. Now, the issue is that the internal reveals are approx 2" to 2.5" wider all around than those outside, and as such, required making up somehow. What I have done is built a solid timber frame to surround the window, then clad this with 1/2" plasterboard to bring it more or less up to internal wall level. All internal walls are back to brick and are being roughed and skimmed when prep is complete.

My question is this....

If the point where the new frame / plasterboard surrounding the window meets the existing brickwork of the walls is meshed tight with EML, then S&C rendered before plastering, is this a solid enough backing to avoid cracking later.???

Of course, I have the option of rendering up the reveals as they were and using a hideous wide PVC trim to make up the difference in the reveal, but really wanted to get a good clean finish with no PVC trims. The look I'm after is one where the window appears built into the wall properly.

Any views on this.?

 

[stevethespreader]

for the look you want why not dot and dab plasterboard around reveals placing a plaster edge bead on the plasterboard against the window , then also allowing 11mm or so of overlap of plasterboard for you to float off then skim, bog standard stuff no need for timber frames and mesh

 

[Makeitstop]

Thanks for the reply Steve.

I'm not sure that your method resolves the problem I was confronted by though, as the join between exisiting brickwork and plasterboard still has to be covered doesn't it.?

It's at this point I'm concerned about any future cracking.

The image below here shows what I have done, and it's the join between the plasterboard cladding and exisiting brickwork which concerns me.

Would this area be ok to be roughed over after strapping it over with EML.?

Let me know if I'm being a numpty and missing your earlier point.

Ta.

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• Makeitstop
• 19 May 2013
• 1

 

[Makeitstop]

The images here show what the reveals were like before anything was done with them. One shows a side on view on a single window and the other a pair in the same room. These have some plastic trims on which is exactly what I want to avoid.

The gaps around these reveals once the trims were removed were as much as 2.5" to 2.75".

What would be the best way to get them done without the trims?

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• Makeitstop
• 19 May 2013
• 1

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• Makeitstop
• 19 May 2013
• 1

 

[stevethespreader]

ok lets see if i can explain take a sheet of plasterboard and cut it to lenghs to fit inside your reveal the edge that sits between the plasterboard and the window is capped with a plaster edge bead this will give you a nice straight line and will help mimimise cracking, the other side of the plasterboard will be cut so that its protruding 11mm past your wall this will then be used to float off your under coat any gaps you have in that area will be filled, then its ready for a skim whos doing your plastering?

 

[Makeitstop]

Thanks again for the reply.

Let me know if I'm understanding you correctly.....

The layer of plasterboard you mention, which are left oversize and edged with the beading are the ones which are fitted within the reveal, closest to the glass and at 90 degrees to the PVC frame yes.???

This oversized strip of board is to allow a render coat to be brought up flush to the beading, and, would cover the point at which the plasterboard meets the exisiting brickwork.

Is that correct Steve.???

 

[stevethespreader]

yes plaster edge beads are put over the board to fit flush against the window, external angle skim beads are put on the outside edges once the wall has been floated ready for the skim

 

[Makeitstop]

Thanks again for the reply Steve, much appreciated.

In the image here, there is a small dialogue box with text in, though I'm not sure you can zoom into it to see it as you'd have to. (Sorry am not sure how to post it already zoomed in).

This shows the point at which I have concerns over cracking. It's the point at which the face of plasterboard cladding butts up to the brickwork, and not anywhere near the plastic of the window frame.

I understand about having a straight edge, left slightly proud to bring the render coat out to, and my plasterer has said not to worry over that as he'll sort how he likes it to be. It's the gap between existing brickwork and plasterboard clad timber frame. This is what I see as a potential weak spot, and, why I suggested metal lathing to reinforce.

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• Makeitstop
• 19 May 2013
• 1

 

[stevethespreader]

ok ive uploaded an album with some pics for you to look you will see a window I done with this method 4 years ago and you will also see a pic I took of it yesterday with no cracks you will also see another window I done with the plastic trim that you don't want both windows had the gaps you mentioned and was far worse than your windows, also ive added another pic of a 70ft bulkhead I done which had an edge bead running 70ft across the window I added that pic so you can see the effect I cant be more clearer than that your spread should know all this
"EDIT" go to my profile to view pics

 

[Makeitstop]

Hi Steve,

Thanks for the images and response.

Looking through your pics there, your window with gaps and the twisted lintel doesn't appear anywhere near as bad as the windows I am referring to. If you take a look at the image attached here, you can see just how wide these gaps were in places. Also, as I'd only just started to rip these out, the plastic trims used to cover these gaps is still in place here and there. This is 2" wide trim, and the gaps behind them once removed are almost as much as a brick thickness. They were ridiculous.

My questions is.....

If they remain framed with solid timber as they are, screwed in tight around the whole reveal, with the plasterboard cladding over that and EML screwed over the joint between edge of plasterboard and existing brickwork, will that offer a solid enough base to avoid cracking.?

That's pretty much the answer I'm looking for.

My plasterer had nothing to do with this, it was my solution to such wide gaps around the reveals. Whether it be right or wrong.

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• Makeitstop
• 20 May 2013
• 1

 

[stevethespreader]

cant you show me some close ups of the said gaps I cant see much in that pic btw my plastic trims in that pic were 90mm, I have just had another look at your pic and the plasterboard you have put up is already level with the bricks? yes? so what are you and your plasterer planning on doing rendering over the bricks and plasterboard? whith eml over the joint? what are you going to use as beads at the corners how is that going to marry in with the plasterboard inside the reveals? or are you planning on rendering that as well? I wouldent be happy with any of that

 

[Makeitstop]

I'll take a few close ups and will post later Steve.

Yes, plasterboard is up to brick level and mesh over the top to secure.

The plasterboard on the inner reveal will be skimmed straight up once the render is sorted over the faces of the walls. The plasterer said to leave battening out the inner reveals for him to render up flush to, as he'd prefer to sort that himself. He does know what he's on about I know that much.

I guess a better thing to have done would have been to get his opinion before I'd framed these up, but then, I have a feeling he'd have said to board them out, which I really wanted to avoid.

Will be back later, just going to stick up some ceiling boards...oh joy.

 

[Makeitstop]

This is an image of the gap at the head of one window still to be sorted.

Believe it or not, this gap is less than at the sides by some margin.

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• Makeitstop
• 20 May 2013
• 1

The image below shows what I have done by way of framing and cladding the reveal. you can see the mesh is placed over the joining point between plasterboard cladding and existing brickwork.

That is what I was wanting opinions on. Is this likely to be solid enough to ensure that once rendered and skimmed over, there shouldn't be any cracking.???

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• Makeitstop
• 20 May 2013
• 1

 

[stevethespreader]

i can see much more clearly your problem now, you are right the gaps were bigger than mine a lot bigger, the first thing i would say is your windows are ill fitted and are not the right size cant you call the window fitters back? also you have made a good atempt at solving the problem but sadly i fear you will get cracks along that joint between the brick and plasterboard even if it has got mesh on it,its in such a position as well where it will take knocks or vibrations where the window opens and closes , board the whole wall maybe?

 

[Makeitstop]

Boarding the whole wall was my plasterers view too, but I've spent time on getting them as good as possible and would rather not go that route.

That window which shows the gap is actually one of the older ones which is going to remain, although after removing the trims and ****e amount of wet Carlite, the horror gaps still need to be sorted.

The newly fitted windows (10 of them in total) are actually fitted as well as they possibly can be, and were taken from external reveal dimensions. Obviously, a window HAS to fit the size of the external reveal, so as the correct amount of frame is visible. Besides, the outside of the house was totally re-dashed, and so that in itself was going to take up a small part of visible frame when the reveals were fined up.

The problem was that the internal reveal is massively wider than it is outside, so has to be made good somehow. I really wanted to avoid the absolutely minging plastic trim route, as they are a bag 'o' ****e. The frame idea was all I could think of, even though it's not ideal.

I am thinking that the meshing might work, but I'm not totally convinced.
Once screwed in nice and tight, and given two coats of render to perhaps 20mm thickness in total to bring the walls up level and good, I thought it might be ok.

You think it'll still go at some point Steve.?