Is it ok to Polyfilller straight onto brick?

Hi,

We have a small section of plaster that has been removed right back to a solid brick internal wall. Will it be ok to fill this whole section in with poly filler? The depth is about 1CM. The height, 10CM, width, 5CM approx.

Image attached.

Just wondering if it is better to plaster this up, or is polyfiller generally ok to put directly on to brick.

Thanks in advance!

Personally, i'd use bonding plaster or mortar to fill the hole to just below the finished level and then use easifill to provide the finish layer.

Polyfilla doesn't like being used in thick layers (it cracks, shrinks and doesn't always cure properly) and multiple thin layers often don't bond very well.

Agree.

Sand and cement mortar is very easy to use, has a long working life, and strong (if you dampen the wall first and prevent it drying out quickly). You can skim it over with finish plaster once it has cured. I prefer S&C for setting electrical boxes in block or brick, but it is fairly slow to harden. it will slump if too wet.

Plaster is also easy to use, sets fairly fast, and cheap. With practice gets a better finish than filler, and does not wash off when wet. But does not store long. Because it tends to shrink and crack, always do at least two coats - one to fill the depth, finishing, say, a quarter inch below finished surface, and after that has set, a thin one, very smooth, to finish. If you have bumps or the surface is too high, scrape it with a broad metal scraper, like shaving, while it is still cheesy. Sanding dry material is hard work and very dusty.

With either of these a metal float is best for larger patches, but a broad filling knife will do for filling chases and small holes, say, as big as an electrical socket. If your knife is wide enough to press on the existing sound plaster at each side, bridging the new, you can press your muck flat, and can scrape off any excess.

For the job in your pic S&C to fill, and Easy to finish, with a metal float, would I think be best. you can get tubs of readymixed board and joint plaster, very good, but they are too big for your little job.

Hi

Thanks for both of your responses. This is very helpful.

Possibly opening up a whole new conversation, given the solid brick wall construction, would lime mortar be the best use rather than sand & cement?

Perhaps given the size/location of the hole (internal wall) there are no concerns about breath-ability, etc?

Thanks