Cracks & lumps in new plaster

We had a list of small jobs that required doing at our house, one of which was plastering. I don't know about the plasterers around your areas but i'm in touch with a lot of plasterers through my work & it seems they don't get out of bed for such small jobs. So for all these jobs we got a handyman that came recommended.

For the most part his work has been perfecto. It's just a couple of issues with the plastering.

1) lumps

He plastered a section of the kitchen. The surface was a bit of a strange tacky surface. 99% of it is perfectly fine, but there's a small section which is quite lumpy.
I'm not majorly bothered as the fridge is going to go where it is lumpy & as such it just wont get seen.

Doesn't stop me wondering WHY it is lumpy when the rest of the plastering is smooth. I took a photo as best i could...



2) Cracking

This is the one that concerns me.

He carried out the job on Thursday. There was a list of jobs so i'm not sure at what point he started this particular one, but he was down for 8:30 & wrapped up by 4:30.
Friday dinner time it was still visibly wet & looked perfectly fine...


I came to it this morning and it had almost totally dried out & there was a whopping crack...



The main triangular piece that is fine is plasterboarded.
The bit that has cracked, underneath this was wood & i doubt he would've boarded this. Originally it did have some 1930s plaster on there anyway.

It looked like this previously...



And then before that...



Now i made sure that the heating wasn't on high, the windows weren't fully open & no dehumidifier was used (my mum made these mistakes & her plaster cracked, although not as bad as this).

How can this get rectified?

This guy is booked up. We had to wait 7 weeks just to get this slot. He's rammed with work.

Problem is, a family friend is coming to wallpaper & ceiling paper that room on 7th November. He's coming from quite far away & his train etc have already been paid for, so we need it sorting by then.

I imagine the ideal solution is to rip it all off & start again. Problem is we can't do that as we don't have the time to get it put right again.

Is there some sort of [insert whatever it is here] we can put over it? I've heard of textured paint for filling in cracks & then there's filler. I imagine whatever is used (if it will work) would need to be somewhat flexible otherwise it'll crack again.

As an aside - why will this have cracked? Is it likely to be the draught from above (the roof)? Though surely not, else the main triangular piece would've surely cracked.

Help very much appreciated.

The crack is caused by shrinkage because he has skimmed onto wood.
You can try a flexible caulk on it and sand it down when dry.

The dimpled plaster can be sanded or scraped back.

The kitchen lumps could be that the backing surface wasn't carefully cleaned off but its more likely that the mixing wasn't thorough - esp. if it was hand mixed.
Or the mixing bucket was dirty.

And as always, powder to water.

Or, the use by date on the bag was passed.

For me: the LH laths should have been removed and a piece of plaster board inserted. Perhaps i'm wrong but the RH side appears to be a wood board, which would make sense. If it is a board then, without special preparation, the skim should not have been applied to it. Merely sand & paint.

Thanks very much guys for the quick replies...

The chap isn't a plasterer by trade, just a jack-of-all-trades kinda guy who can do a bit of this & a bit of that, plastering being one of them. Much better than i could do but obviously not the level or perhaps knowledge a full time plasterer has.

I did try getting plasterers out to the job but like i say, none of them would bother as the job was so small. They'd say they were all busy, but rather than "i'm busy but i can fit you in in 3 months" it was just, i'm busy. I got the clear impression the job was too small for them.

alastairreid said:

The crack is caused by shrinkage because he has skimmed onto wood.
You can try a flexible caulk on it and sand it down when dry.

Click to expand...

I get the impression you don't know whether that approach would work or not? Just a try it & see kinda thing?


I bought some Wurth sealant for a few jobs a little while ago & i have some left. Would this be ok for the job?
http://www.ebay.co.uk/itm/140789976469?_trksid=p2060778.m2749.l2649&ssPageName=STRK:MEBIDX:IT

Or would it need to be some other sealant?

ree said:

The kitchen lumps could be that the backing surface wasn't carefully cleaned off

Click to expand...

Perhaps as it was a really strange surface. Hard to describe. A bit slimy but we had a go at cleaning it up. It was still a strange feel.

but its more likely that the mixing wasn't thorough - esp. if it was hand mixed.
Or the mixing bucket was dirty.

Click to expand...

It wasn't hand mixed as i saw his drill & paddle thing but i don't know how clean the bucket was.

Or, the use by date on the bag was passed.

Click to expand...

Again i'm not sure on the date as i never saw the stamp but the back was unopened. I know this doesn't guarantee being in date but that's all i saw.

Strange though that it's only lumpy in that one section. The rest of it is nice & smooth.

For me: the LH laths should have been removed and a piece of plaster board inserted.

Click to expand...

I don't know if he removed the laths. I am guessing not as i have various rubbish bags around the rooms we're doing work in & he's used them but i see no laths in there. But he did use the plasterboard i provided (i'm able to get offcuts so rather than paying for a full sheet i got an offcut free)

Perhaps i'm wrong but the RH side appears to be a wood board, which would make sense. If it is a board then, without special preparation, the skim should not have been applied to it. Merely sand & paint.

Click to expand...

Yeah the right hand side, that thin strip piece is wood. It's coated in something a strange pinky colour, similar to the rest of the ceiling so perhaps all the old 1930s plaster?




What i'm bothered about is papering the ceiling & then all this plaster falling off in big chunks.



On the topic of which... How should you go about preparing the plaster for papering?
I know with painting you go a 50/50 paint/water mix with that Dulux Supermatt stuff before you think about putting your finishing coat on.

Do you do anything similar to prepare for wallpapering or should i really ask in the decorating forum?

Thanks again for the replies guys.

The small lumps/bumps are blisters. The crack, as Alistair said, is where the wooden bead has swelled up cracking the plaster. I often do this type of work on old dormers, and with the right prep, you wont get any cracks. You can even fit a corner bead giving a neat crisp angle. The joints between the wooden bead and the plaster either side always need taping first just like any other joints.

Ah that makes sense.

Would something along the lines of this be ok...

http://www.diy.com/rooms/polycell-c...-matt-smooth-emulsion-paint-25l/127228_BQ.prd

The ceiling itself is quite badly cracked so if this is any good for the bit shown in the photo then it can get painted over & also used to do the ceiling before it's papered.

Looking at the ceiling it looks like the previous owner (or one of them) has had a do at painting over the cracks anyway but no idea what with.


However if this would be no good for the bit of plaster that has cracked, would that Wurth sealant i've got be ok to put in or is some other type of sealant better for the job?[/quote]