Hi all,
My first post here but I've been lurking over the years and found plenty of sage advice.
I've got an external parapet wall c.1925 that has been wet dashed with granite in the usual Scottish manner. About 20 years ago I had the loose copes rebedded (they bed onto a lead flashing that covers the top of the wall) and patches of bossed harling stripped and redone.
Over the years the unpatched dash coat has worsened (probably due to the copes being a bit narrow with insufficient drip-off) so I've stripped off the harling back to the brick for the top 2 foot. The top row of bricks especially have spalled badly and are crumbly so I've been advised to use riblath to get something decent for the new harling to get a hold on.
I'm doing the basecoats myself this time, then a roofer friend is going to wet dash it for me. I've been told that you need to do 2 scratch coats on riblath and I've also read the same on here somewhere (by Micilin I think).
Not being a tradesman (I'm a marine engineer), is the reasoning that the prick coat stiffens up the lath? Do you coat over the riblath (prick coat) till you've got a couple of mill over the metal then scratch that, then level it out with the 2nd scratch coat, as I'm told the lath goes quite uneven once it's fixed to the wall.
Also, where the bricks are badly wasted back I was thinking of doubling up the riblath to make it stiffer as there'll be a gap of about 18 inches where I won't be able to get a fixing to the wall.
Also, what mix should I use for the prick coat, normally I use 4 to 1 on a scratch coat, would that be ok? And how about Freeflo, I was going to put it in to re***d it a bit as I'm not a fast worker, would that cause the prick coat to slump too much through the mesh?
All help gratefully received, thanks
My first post here but I've been lurking over the years and found plenty of sage advice.
I've got an external parapet wall c.1925 that has been wet dashed with granite in the usual Scottish manner. About 20 years ago I had the loose copes rebedded (they bed onto a lead flashing that covers the top of the wall) and patches of bossed harling stripped and redone.
Over the years the unpatched dash coat has worsened (probably due to the copes being a bit narrow with insufficient drip-off) so I've stripped off the harling back to the brick for the top 2 foot. The top row of bricks especially have spalled badly and are crumbly so I've been advised to use riblath to get something decent for the new harling to get a hold on.
I'm doing the basecoats myself this time, then a roofer friend is going to wet dash it for me. I've been told that you need to do 2 scratch coats on riblath and I've also read the same on here somewhere (by Micilin I think).
Not being a tradesman (I'm a marine engineer), is the reasoning that the prick coat stiffens up the lath? Do you coat over the riblath (prick coat) till you've got a couple of mill over the metal then scratch that, then level it out with the 2nd scratch coat, as I'm told the lath goes quite uneven once it's fixed to the wall.
Also, where the bricks are badly wasted back I was thinking of doubling up the riblath to make it stiffer as there'll be a gap of about 18 inches where I won't be able to get a fixing to the wall.
Also, what mix should I use for the prick coat, normally I use 4 to 1 on a scratch coat, would that be ok? And how about Freeflo, I was going to put it in to re***d it a bit as I'm not a fast worker, would that cause the prick coat to slump too much through the mesh?
All help gratefully received, thanks
