Plaster cracks

[Pocster]

Hey all

 

my spec shows insulation in between rafters then 50mm over that whole thing finished with taped joints . So when I plasterboard I just screw straight through the pir into the timber ? . I’m worried on a timber frame build that once skimmed there’s bound to be some movement and plaster cracks ?

even on a masonry build you always get hair line cracks where ceiling meets external wall . There a simple trick to avoid this ? Just calk the edges ???

just assume chance of skimming cracking higher on timber frame build ....

 

cheers 

Edited January 26, 2018 by pocster

[lizzie]

As its all drying out mine is cracking....going to drive me nuts!

[Pocster]

7 minutes ago, lizzie said:

As its all drying out mine is cracking....going to drive me nuts!

Drying to quick ? . Or if sun light is hitting one part and not another will cause shrinkage !!

[lizzie]

No drying very slowly and not a sun problem.  Its timber frame, I am told it is inevitable with timber frame as the timber frame does have a degree of movement. We were immensely careful with the skimming and the joints on the boarding but I still have some cracks. One on the ceiling in my kitchen and one or two on walls.

 

I guess its not that bad its just that I hate cracks and I notice every little one.

 

We looked at using a German wall covering product (as used in the high end German prefabs) instead of skim but every decorator I approached to put it up started the sucking through teeth thing and shaking the head whilst £ signs were floating in the air.  In the end it was easier to go the conventional route with skim.

 

If you want details of the wall covering product let me know.

[Pocster]

5 minutes ago, lizzie said:

No drying very slowly and not a sun problem.  Its timber frame, I am told it is inevitable with timber frame as the timber frame does have a degree of movement. We were immensely careful with the skimming and the joints on the boarding but I still have some cracks. One on the ceiling in my kitchen and one or two on walls.

 

I guess its not that bad its just that I hate cracks and I notice every little one.

 

We looked at using a German wall covering product (as used in the high end German prefabs) instead of skim but every decorator I approached to put it up started the sucking through teeth thing and shaking the head whilst £ signs were floating in the air.  In the end it was easier to go the conventional route with skim.

 

If you want details of the wall covering product let me know.

You would of thought there would be some internal render with some form of flexibility by now ?

Im sure others will jump in with a solution .

Like you I hate the cracks ! Brand new build should have no cracks ever ?

[Luckylad]

I would counter batten over the pir board because it's bit spongy and you'll get screws popping. I think you'll get better u value, a service void and you'll see what you're screwing into, rather than guessing through the pir.

[Luckylad]

38 minutes ago, lizzie said:

 

If you want details of the wall covering product let me know.

Yes please, sounds interesting

[lizzie]

We counter battened our entire ceiling - the 25mm service void provided by frame suppliers was not enough for our lighting so we had to increase it by counter battening.  Still got a few ceiling cracks.

[lizzie]

2 minutes ago, Luckylad said:

Yes please, sounds interesting

http://www.theglassfabriccompany.co.uk/

 

http://www.systexx.com/en/products/downloads.html

 

 

 

[Pocster]

39 minutes ago, Luckylad said:

I would counter batten over the pir board because it's bit spongy and you'll get screws popping. I think you'll get better u value, a service void and you'll see what you're screwing into, rather than guessing through the pir.

I think my architect wanted no thermal bridge . Insulation in between rafters then 50mm over that and the rafter edges .

so complete insulation back to back 

[nod]

1 hour ago, pocster said:

Hey all

 

my spec shows insulation in between rafters then 50mm over that whole thing finished with taped joints . So when I plasterboard I just screw straight through the pir into the timber ? . I’m worried on a timber frame build that once skimmed there’s bound to be some movement and plaster cracks ?

even on a masonry build you always get hair line cracks where ceiling meets external wall . There a simple trick to avoid this ? Just calk the edges ???

just assume chance of skimming cracking higher on timber frame build ....

 

cheers 

If u get any movement Plaster will crack No matter what precautions you take Timber frame are more likely to crack 

years ago when we used to artex We stopped putting tape around the edges as it was so difficult to patch artex We would let it crack then cork the edge when the heating went on

 

The easiest way to deal with a hairline crack is to make it bigger

Gently tap a bolster along the crack to make a 2 mil deep V Chanel and fill with a good quality flexible filler 

 

 

 

[Declan52]

Just let it sit for about 18 months and let it move and crack and finally settle. Then go round and fill and sand. It will happen on every build no matter what you do as it dries out. If you fill as every crack appears then you will go mad in no time and end up doing the same crack a few times.

[Pocster]

No ones invented breathable flexible internal render ?

why not ?

[Roger440]

56 minutes ago, pocster said:

No ones invented breathable flexible internal render ?

why not ?

 Why not indeed?

Frankly, its amazing we a still messing around with plaster for stuff like this in the 21st century.

But progress is slow in the building game.

[ProDave]

One thing I have observed.

 

A "normal" build where the frame goes up, the services go in and the plasterboard goes on, as quick as possible, seems much more prone to issues like this as the frame settles.

 

Our frame has been standing for 2 years now The first plasterboard went on last year and then a while later the plaster.  It is my perception that the frame has done most of the settling it is likely to do now, so cracks are less likely.

 

There are advantages to being slow.

[Pocster]

3 minutes ago, ProDave said:

One thing I have observed.

 

A "normal" build where the frame goes up, the services go in and the plasterboard goes on, as quick as possible, seems much more prone to issues like this as the frame settles.

 

Our frame has been standing for 2 years now The first plasterboard went on last year and then a while later the plaster.  It is my perception that the frame has done most of the settling it is likely to do now, so cracks are less likely.

 

There are advantages to being slow.

Slow I can do ?

[Gone West]

10 hours ago, ProDave said:

Our frame has been standing for 2 years now The first plasterboard went on last year and then a while later the plaster.  It is my perception that the frame has done most of the settling it is likely to do now, so cracks are less likely.

 

That has been our experience as well. Our frame had been up for four years before it was plasterboarded. It was skimmed a couple of months later and we had virtually no cracks.

[nod]

10 hours ago, ProDave said:

One thing I have observed.

 

A "normal" build where the frame goes up, the services go in and the plasterboard goes on, as quick as possible, seems much more prone to issues like this as the frame settles.

 

Our frame has been standing for 2 years now The first plasterboard went on last year and then a while later the plaster.  It is my perception that the frame has done most of the settling it is likely to do now, so cracks are less likely.

 

There are advantages to being slow.

Good point Dave

In some cases first fix plumbing is done before it is water tight

No time to dry out 

 

I went to tile a 70 mtr floor last Tuesday No UFH No Matting wanted The Builder said it’s bone dry We SBR the whole floor Two hours later still wet The following day we tiled it But still should have been left a bit longer All the skirtings a internal doors stacked in the garage

I guess there not going to leave it a week to walk on it 

[Brickie]

I’d guess the traditional method of timber Lath & 3 costs lime plaster would significantly reduce cracking,as the lime has a bit of ‘give’ in it & with a 3 coat system each coat takes a bit of any shrinkage/expansion exerted on it before its transfers to the next. Expensive way to do it though,unless you were doing it yourself (Pocster-don’t even go there!)

[Pocster]

53 minutes ago, Brickie said:

I’d guess the traditional method of timber Lath & 3 costs lime plaster would significantly reduce cracking,as the lime has a bit of ‘give’ in it & with a 3 coat system each coat takes a bit of any shrinkage/expansion exerted on it before its transfers to the next. Expensive way to do it though,unless you were doing it yourself (Pocster-don’t even go there!)

Lol !

i know some of my limits ! Wouldn’t even attempt it !! . You would of thought though some resin type flexible wall screed existed by now . Can you not just invent one and go on dragons den for funding ? ?

[Pocster]

Actually in Florida for example virtually all builds are timber frame . Inside nice smooth walls no joins or cracks . Weather can change rapidly in temperature from lovely sunny to actually cold with a torrential down pour . So the frame must be moving . What do they do ?

Any Florida house builders here ??? ?

Edited January 28, 2018 by pocster

[Brickie]

Seasonal movement is one thing-what we’re talking about here is settlement cracks in the early life of a new build. 

Ive not been to Florida but if that’s the local method most used then maybe they’ve a culture of seasoning the timber before it’s used in construction,reducing the potential for shrinkage & settlement. 

[Ian]

We’re now in our second winter of using our timber frame and timber clad holiday home and still no cracks in the skimmed plasterboard walls or ceilings.

 

The timber stick frame was pre-manufactured offsite in sections and then erected and made weathertight in a nice warm dry spell in the early summer of 2016 in the space of just 2 weeks. Before the start of the winter we had the concrete floor slab properly dry and the underfloor heating working.

 

None of the timber frame building structure had the chance to get wet and I think that’s probably the main reason why we haven’t had any shrinkage cracks in the plastered walls.

Edited January 28, 2018 by Ian

[Pocster]

Ok!; anyway!; back to my original problem 

 

Insulation between rafters ; 50mm over the lot. Plasterboard fixes how?. The point of the 50mm over is to avoid all thermal bridges; so just upping with timber battons I guess doesn't help.

 

Cheers

 

 

[Ian]

@pocster

Isn’t this the usual way of doing it: insulation between rafters and wall studs then continuous layer of PIR over the face then battens to create a wiring zone.