Help - plaster crumbling near skirting board!

kaboo

Hi all,
I am in need of some wisdom. I bought my first home, a beautiful 3 bed semi built in 1930s. While repainting I found that in the reception room, at one of the corners, old paint was looking funny. It felt very uneven and upon plaster felt soft and spongy! Knocking with my knuckles produced a very hollow sound. I tapped quite hard and a small chunk of plaster came off!!! Crumbling plaster was being held back by layers of paint!

I then thought that I need to fill this hole again and bought a small tub of polyfilla for deep gaps. As per the instructions I tried to get rid of any loose material. I did not try too hard and did not use much force, but just simple prodding with putty knife brought down good chunk of material. If I try I can break off more material but I stopped when the plaster seemed more sturdy. I am attaching pics. The plaster is over a brick wall.

My plan is, dust with a wire brush gently, clean with damp cloth, paint with VPA primer, then fill with Polyfilla Plaster Repair, smooth with a trowel, and sand after drying. Does this make sense?

But my main question is, as you can see in the pic, there is a gap behind the skirting now. Looks like plaster between the bricks and skirting has fallen through into the floor below the floor boards. What should I do here? Can't just keep filling with plaster repair filler!

Many thanks

 

FreeBear

Scrunch up some newspaper to fill the gap and then whack your filler in. Build it up in thin(ish) layers to reduce the chance of it cracking.

The "right" repair would be to use a lime plaster, but I doubt that you would want to go out and get a tub of lime putty or mix the stuff yourself.

kaboo

Thanks, I dont have lot of experience with this stuff. So dont know if I want to use Lime plaster or not. Is it easy to use - like a filler? Can it be bought ready made?

Most plaster repairs I have done were in the previous houses I was renting - filling holes made by screws or nails with multipurpose polyfilla. The biggest hole I filled was like 4 cm in dia in plasterboard and I sued one of those metal meshes to paste over and then cover with polyfilla general purpose.

TELLIT01

A standard tub of plaster isn't lime plaster so just use normal stuff.  Plaster can 'blow' over time but the good news is that there doesn't seem to be any evidence of damp.

kaboo

Thanks, yes we had 3 surveys (1 sellers, 1 buyers, 1 lenders ) no damp was found. I can try lime plaster if I can find it in B&Q and it its easy to use by a newbie DIY'er!

stuart45

I doubt if you will find any lime plaster in B&Q.  This is a lime based filler in Wickes, but is really designed for tape and fill.
Knauf Fill and Finish Light - 5kg | Wickes.co.uk
For a small area like yours it doesn't matter so much what you use, but if you find a lot more blown areas it might be worth investing in some lime putty. You can then mix up your own plaster with a coarser sand for the base coats and fine for the finish coat.

FreeBear

kaboo said: I can try lime plaster if I can find it in B&Q and it its easy to use by a newbie DIY'er!

Absolutely zero chance of finding lime plaster in B&Q or any of the other DIY sheds. If you want a ready-mix, you'd need to go to a specialist supplier like Mike Wye (other suppliers available). But shipping costs will make in nonviable for small quantities.

It does need a bit more work when compared to modern gypsum plasters - Biggest issue is cracking as it dries, so you need to go back and "work it over", usually with a flat wooden float. On the plus side, I think it a little more forgiving than something like Multifinish. Keep it damp, and you can go back and rework it. Also, a tub of lime putty plaster doesn't go off, so as long as you keep it in a sealed tub, it will remain usable for years.

bris

Use a PVA glue to seal it, then build it up in thin layers using the Screwfix No Nonsense ready mixed plaster. I use it all the time, it's great for the job, just remember the trick is thin layers.

kaboo

Okies... I think will try to read more. MAny thanks for all the replies, really boosted my confidence. I was about to press panic button thinking my new house is going to come crumbling down soon

There is evidence of patching/fixing plaster all across the house, mostly ground floor. So I guess its a std thing in old houses. It will be good to learn how to fix and also have a good material at hand. 

So Screwfix No Nonsense ready mix would be better than Polyfilla?

kaboo

One more things guys - which tools will I need? A trowel and joint knife?

cattom

ask a plaster if he wants a cash in hand job one weekend.