Painting/filling sandstone

VanMan2007

I recently read a helpful thread about painting plaster, which advised painting with a coat of half paint + half water, due to the porous nature of fresh plaster.

Would the same/similar apply to sandstone? I have sandstone blocks under my bay window and a block above my front door. Both need slight "filling" in places as well.

So: what kind of filler is best? Presumably treat with PVA before applying it? And what is the best way to achieve a cost effective good result when painting sandstone with masonary paint? Also, what is the best way to clean prior to painting?

Thanks guys.

rubble2

I did the same thing with our sandstone bays last year. I used Toupret Murex Exterior Filler (got it from Toolstation - £12.27 per pack).

It works well, is easy to sand down and still looks fine 12 months on.

Regarding the painting, I stripped all the old paint off using a heat gun and then repainted the Sandstone with masonry paint however I then got problems with brown stains showing through the paint after a week or so. I think that I should have treated the sandstone with some form of primer before the masonry paint. I found that I couldn't strip the new paint off again effectively but eventually got round it by painting the stone with Oil based white undercoat before re- applying the masonry paint.

That seems to have solved the problem.

Hope this helps

VanMan2007

rubble2 wrote: »

I did the same thing with our sandstone bays last year. I used Toupret Murex Exterior Filler (got it from Toolstation - £12.27 per pack).

It works well, is easy to sand down and still looks fine 12 months on.

Regarding the painting, I stripped all the old paint off using a heat gun and then repainted the Sandstone with masonry paint however I then got problems with brown stains showing through the paint after a week or so. I think that I should have treated the sandstone with some form of primer before the masonry paint. I found that I couldn't strip the new paint off again effectively but eventually got round it by painting the stone with Oil based white undercoat before re- applying the masonry paint.

That seems to have solved the problem.

Hope this helps

Thanks rubble2, my sandstone on bay and above door is bare, so showing signs of weathering, but I don't have your repainting problems.

Thanks for posting tho.

HarriDec

Don't use PVA whatever you do, it will be a nightmare. The masonry paint will just slide over the top. A thinned coat of masonry paint (20-30% water) will be fine.

Clean down with detergent/sugar soap first. There is a professional product that we use called Krud Kutter but may be a bit overkill for a DIY project.

Use Toupret filler on the imperfections, but not Murex. The cement based one is much easier to use and rub down. Seal the filler using an oil base primer such as Zinsser Cover Stain.

You can find more painting and decorating advice on our website and in our blog, click the link!

VanMan2007

Brilliant. Thanks HarriDec, just what I wanted.

:T