5 posts / 0 new
Last post
Scratch Coat for Stone Veneer

I installed lath and a scratch coat for a stone veneer; however, I believe I mixed the mortar too stiff and it turned out brittle and chalky (plus I didn't let it set before hitting it with the notched trowel). I knocked down the tops to make it a little more solid, but I'd like to know if there is a repair I can do to harden the surface, or should I do the scratch coat again?

Re: Scratch Coat for Stone Veneer

Start from the beginning.

Re: Scratch Coat for Stone Veneer

I don't think you mixed it to stiff.
It most likely dried reather than hydrated.
If it has a bond to the lath and you can't remove it by pressing on the lath you should be able to apply a second coat of the following.
1 Part Portland Cement
1/2 to 3/4 parts Masons Lime
4.5 Parts sand
After you have applied this coat make sure you mist the surface with water to keep it from drying out Mist about four hours after it was applied than as required to just keep moisture available on the surface.

Re: Scratch Coat for Stone Veneer


Thanks for your help. How much water would you add to your mix? Or what consistency should I try to achieve?

Re: Scratch Coat for Stone Veneer

If the mortar will stay on trowel when you turn it so the mud is on the bottom you should be go to go.
I use a margin trowel dip it in the mortar get about 1 inch of mortar as wide as the trowel and invert it.

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.