Rob_Impreza99

iTrader: (3)

The house we have is approx 60 years old, ive just stripped a room back to bare walls. The walls were cement rendered then skimmed, the plaster has been allowed to dry out naturally for approx 3-4 weeks with no heat source in the room whatsoever.

Now we have a few cracks appearing, some are quite decent sized cracks. One of the cracks runs right along the width of the chimney breast. I can't start painting as these will show up, why should new plaster crack in this way especially after you have gone back to bare walls and had it rendered and skimmed ?

A few pics of the cracks

fitzscoob

Hi Rob

I'm not in the trade so cant help you at all, but wasnt this the room where you had a damp issue after the plastering?

Could the added moisture in the room cause this?

Rob_Impreza99

iTrader: (3)

That was in a different area to where the cracks have appeared, the small area of damp was on the floor and not on the walls. We had a building surveyor check that out, he was of the opinion that the plasterer had rendered too low and it needed cutting back. He also said that water could have built up in that area from when firstly the cement rendering was done when the plasterer sprays water onto the walls and it built up in a small channel between the floor and wall under the window and held in that area, also excess moisture coming out of the render into that area as well.

He drilled the outer walls and found no evidence of damp.

The cracks arn't on that wall, they are on theother walls. The main cracks are on the chimney breast, the original small area of damp on the floor was under the window.

Leslie

Not an expert but perhaps the plaster shrinks as it dries thus causing the cracks. Maybe when you are sure all the cracks have appeared you will have to fill and rub down the cracks with Polyfilla or some equivalent.

Les

Coffin Dodger

As Les says the best bet is probably just to fill and sand the cracks. I suspect the issue is down to how well the surface was sealed before plastering over, depending on the absorbency of the surface being plastered onto a good few coats of diluted PVA may be needed before it stops soaking in. Even then there is not guarantee that it won't crack somewhere.

If you went back to the brick work why did you decide to go for render and skim? I'd have had it dry-lined, much less likely to crack, and should give a better finish generally.

Rob_Impreza99

iTrader: (3)

Because at some point in the past the room had a full damp course put in which meant that their was a 3 ft area of solid grey plaster all round the room, the plaster's advice was to knock off all the old plaster above the 3ft of grey plaster and his original method was going to be dot and dabbing the room above the 3ft area of grey plaster. I wasn't keen on having plaster board hanging in the air above the grey plaster, if it had been dot n dab to the floor then i may have considered it.

I took advice on here and the common consensus was to cement render the bare walls above the 3ft of plaster then have it skimmed.

Peanuts

iTrader: (15)

Houses move, plaster cracks its a fact of life.
Websense dictates that I cannot see the hosted pictures unfortunately.

You can "V" out the crack and use filler before painting.

cookstar

iTrader: (6)

My guess is the rendering wasn't sealed enough before skimming.

Just one of those things, nothing a little bit of filler wont solve.

Rob_Impreza99

iTrader: (3)

Ive seen how brittle plaster is from a skim when i was trimming the bottom of the walls away to leave a bigger gap to the floor as the render and skim was too low, i would be frightened of cracking the plaster even more than the cracks are by doing anything on the main surface as it could spider all over the place.

Would using backing paper be an option when i get it decorated, i wanted painted walls. Would you see any of the joins if a decorator used backing paper than painted over the top ?

I'm considering all options as i don't want to paint it and more cracks appear, a few have appeared already and you would thing because a few have a appeared already then more may appear once painted.

mamoon2

Have you rang the guy that plastered it for you? Surely he can advise or sort the problem for you?

I remember reading your original thread where two scoobynetters were arguing about the two methods. I bet the guy who was defending dot and dab will be along shortly to gloat

Rob_Impreza99

iTrader: (3)

I wouldn't have him anywhere near the walls again, i had to get him back to patch in a low spot where i could get all my fingers inbetween the wall and skirting board and also on another wall he had a high spot where it would have been difficult to get a skirting board on. For the money he charged i should have walked into a perfectly finished room.

Whats the best way forward with these cracks as their are a few appearing ?

If you got a decorator to put backing paper then painted the walls would you notice the joins on the paper or would they be invisible ?

salsa-king

BEING A DECORATOR.

They look like drying out cracks to me.
Whats your plans for the walls? painting?

get a wash coat on... a very thin coat of emulsion... rake out cracks and fill with FILLER, then sand smooth.
then Re paint with two/three coats of emuslion, ease each coat as not to put it staright on out the tin (use TRADE paint not retail)

if you're worried you can always use a fibre lining paper.. like WALLROCK.
http://www.erfurtmav.com/index.php?o...d=59&Itemid=46
youcan get it from Crown Decorator Centres (about £8-£10 a roll)


this an then be painted over nd will hold off the slight cracking.

WRXBOB

Firstly:
Plasterborads have cracked plaster as much as, if not more than new solid walls!!!



Anyways, your cracking is nothing to worry about as long as the plaster doesn't sound hollow when you tap the backs of your fingers against it.
If it DOES sound hollow, then its not stuck against the base layer of render and would need to come back off.

Assuming it is stuck to the wall ok, follow the advice above regards painting and filler and you'll not see it after. In fact, you'd be amazed what a couple of coats of good paint can cover up!

alanbell

iTrader: (6)

sounds (looks) like the plasterer renderded the wall in one thick coat, he should have scrath coat (base coat) it first let it dry a bit then 2nd coat it , then leave for a day then skim, if you put render on in 1 coat to thick it will crack when it drys.
Render done right is much better than dry lineing >> dot and dab

Dedrater

No chance this is the Plasterers fault or anything to do with the render he was applying it to ffs.

Think about how a skim goes on and the consecutive lines.

Dedrater

No chance this is the Plasterers fault or anything to do with the render he was applying it to ffs.

Think about how a skim goes on and the consecutive lines.

stevebt

iTrader: (8)

Bollox, the walls can be done in one go(two coat work) no problem giving a wall a scratch coat then plastering allows for more shrinkage or more problems.


Sand cement is a **** and if not applied right or the right mix you get what you have I have just done 2 rooms for someone today and it used to be original solid plaster but I have dot and dabbed the walls and it is just a quality job as the walls are warmer to the touch and its just a better job. Getting someone to render internal walls on a property is madness as there is no need for such archaic materials. Those cracks are really bad and I bet if you tap on the wall it will have a hollow sound which will definately mean its down to application My house is a 30's house and its all solid plaster and its full of cracks I have tried to repair the cracks and it cracks alongside of the repair. All the work I have boarded over is excellent and its getting to the point where I'm just thinking of stripping the walls and boarding over the rest.

I have just thought aren't you the person that was asking about what to do with the room about a month ago??? As far as I could tell you stripped the plaster off brickwork and told the plaster he had to sand and cemet?? Brickwork walls that have been stripped will have the least suction possible and getting a render coat to apply properly will be a nightmare as you can plainly see. Most of the blame for the cracking will be on you and your decision.

Rob_Impreza99

iTrader: (3)

With not being an expert on building work i took the main advice from people on the other thread where i asked what was the best method to plaster the room from the pics i posted below, the common consensus seemed to be that rendering the walls was the best method because of the 3 ft of grey plaster around the bottom of the room which the plasterer said was best to leave on. People were impying that dot n dab wasn't really suitable for walls that already had plaster around the bottom as its more suitable for walls that are full stripped bare.

Ive tapped the area where the main cracking is on the chimney breast and it feels solid, it doesn't feel hollow. The cracking is above the grey plaster area so its where fresh cement render and skim went on.

Here are the pics from before.

stevebt

iTrader: (8)

Those cracks aren't along the line of the original plaster as if they were they would be straight, but the plaster at the bottom doesn't have anything to do with damp etc as if it did it would have holes drilled in every few inches. If the consensus was to do it in icing sugar would you do it It was your decision and it was a bad call.

Rob_Impreza99

iTrader: (3)

I'm after advice on this thread as to which is the best way forward now, if it was a wrong decision then it was a wrong decision.

It just seems to me like your here on a gloating trip with a reply like that because you suggested dot n dab previously against the majority which said rendering was the best option rather than offering any advice to move forward, obviously with no experience of this i'm going to go with the majority of opinions because wouldn't you do in an area your not familiar with when your asking for advice ?

I just want advice to sort the cracks, not whether the method was wrong or right.

Nobody can say 100% that cracks wouldn't appear in dot n dab as well, i'm sure they do! From my research a lot of factors can cause cracking in plaster.

Dedrater

Steve, I know you are a Plasterer et alibi, hard to say I know if you can not see directly, obviously.

But, Plasterer fault?

Dedrater

Steve, I know you are a Plasterer et alibi, hard to say I know if you can not see directly, obviously.

But, Plasterer fault?

Rob_Impreza99

iTrader: (3)

The plaster on the chimney breast was left like that, the plasterer said thats fine as its bonded strongly.

I'll have to double check tomorow but the lines follow a similar shape to that grey plaster on the chimney breast and the crack could just be above it or in a direct line with that grey plaster line.

Dedrater

Not his intention, I'm sure.

Trade guys don't take anything lightly, to do with their Trade...

fast bloke

Paint it, leave it for 6 months, fix all the cracks and paint it properly. I would go with alanbell's view on the finish. Dot'n'dab is always a low cost low quality option. Whatever you do, don't consider lining paper.

alanbell

iTrader: (6)

pva the chimney breast fit thinwall beads over corners scrim over the cracks, skim full breast, steve,s wrong im right, (morning steve)

alanbell

iTrader: (6)

just to add dry lineing , dot & dab came out to replace light weight plaster on new builds
and is not used any were near damp condisions , the first time i used this is about 35 years ago , Its ok in the right place , (DRY)

stevebt

iTrader: (8)

Morning Alan If you look back at his other thread I suggested renovating plaster as a proper modern alternative which is far superior to any sand and cement job. The crack can only be appearing due to application or mix as I said before. I would hack a bit of the wall off where it is cracking to make sure it does have a proper hold of the brickwowork as like I said earlier as well the bricks are low suction and the fact they have had plaster on them before make them have even less suction.

And derader is right Im not here to gloat just explain possible causes as its only the plastered who can put it right and to determine how bad the cracks are from a couple of pictures is really hard but what you can see is that they are really bad to show up on camera like that!

Rob_Impreza99

iTrader: (3)

Steve, thanks for your input. I can see from your last reply that you wasn't gloating.

Ive had a good look round the walls today and their are more cracks than i realised, some are not as bad as others. Some are fine cracks that go all over the place, the concern i have is that if they have appeared now what will it be like in 6 to 12 months time. Those hair line cracks could become full blown cracks, the worse one is on the chimney breast which i posted in pics above.

Its very difficult to see but ive highlighted in pencil on the walls at least 7 that are showing up, their could be more. In your opinion is this likely to get a lot worse seeing so many have appeared in just approx 4 weeks since it was plastered. I wanted to get on with the room by putting coving and skirting board on but the walls concern me, i certainly can't have it painted just yet.

Is it something that i should repair myself or is it a case of things will only get worse where i repair one and others start to appear, how do you go about repairing cracks in new plaster ?

I had a look on youtube and a couple of vids said that you channel the cracks it with something like a blunt, thin screwdriver and fill them and put some kind oc crack tape over the top ?

stevebt

iTrader: (8)

You should not have to repair cracks in new plaster, these cannot be repaired by yourself and I would get the plasterer involved as if he has pride in his work he will sort it out! If I had to guess I would say a strong mix of say 3-1 which although most people say to do it it doesn't work well. Im really curious on how he prepe'd the walls 1st as I know what I would do but I don't know what he did?