patching a crack after plastering

Status
Not open for further replies.
H

herds

New Member
I recently skimmed a chimney breast and a 1 meter long crack line has appeared, i know that the crack has formed above where the original plaster has met the patching I did with bonding prior to skimming.

Sure fellow plasterers have had this kind of hairline crack appear before. Do i sand over it? open it and fill it with something? or just ignore it? Skimming it again isn't really an option.
 
The crack has probably formed along the join because it dried out too quickly or the room was too warm. The easiest way to reslove the issue is to rake out the join and fill with Easifill. Make sure you fill it proud because it will shrink back. When it's dry, simply sand gently and feather it out. Good luck :-)
 
that's good, have a bag of easifill 20 still.

interesting, the house has no central heating so surprised it dried too quick. Perhaps I should have wet the wall with the spray bottle after it had dried?
 
It's not common practice to wet plaster after it has set.

The crack may have appeared because you did not seal the background properly or you let the bonding dry too much before skimming. In each case, water would have been drawn out of the plaster too quickly and hence the crack has appeared along the join :-)
 
Minh said:
It's not common practice to wet plaster after it has set.

The crack may have appeared because you did not seal the background properly or you let the bonding dry too much before skimming. In each case, water would have been drawn out of the plaster too quickly and hence the crack has appeared along the join :-)
Click to expand...

it must be that one then... the patching was about 2 months old.
 
When plaster dries too quickly it shrinks. You'll be able to see this clearly if you were to apply bonding to a high suction background. As it dries you'll notice that cracks appear. It's easily prevented if the background is splashed with sufficient water to reduce the suction :-)
 
Learning everyday :) so next time I skim over dry bonding (left for a week or more) I need to give it a good dose of water before.

Just a question.. could i just not put a more concentrated pva coat on the bonding area? or just 2 regular coats over the bonding area?
 
An experienced spread will wet the bonding and continue wetting it until it becomes saturated. You can use a 5:1 followed by 3:1 solution of PVA to seal the bonding but it will require about 3-4 coats because bonding absorbs water like a sponge. Using PVA to seal a surface is not quantifiable in simple terms, you basically keep applying successive coats until the PVA remains tacky for a good 10 minutes :-)
 
Last edited:
Have you done that bay window yet herds?? get some pics up if you have marra..............:RpS_wink:
 
another thread like that one and you'll be in the private section in no time................:RpS_thumbup:
 
Status
Not open for further replies.

Share this page

Back
Top