Cement rendering engineering bricks - Any precautions on rendering engineering

[ianh64]

Do I need to take any special precautions to render red engineering bricks (FS)?

I am building a small retaining wall that (labour excluded) due to its oval shape is most economically built with engineering bricks - 2 course of DPC + coping was about 1+1/3 pallets of bricks of wall that varies in height between 2 and 7 courses. I am getting slightly concerned that I may have a problem cement rendering the engineering bricks that I have purchased.

Also, as its my first rendering project, I would like some advice on the use of beading. As its an oval shape wall I am expecting it to take some time to get the shape and position of the beading right is critical to achieving clean lines of the wall. At what stage is beading fixed in place and how is it held in place? I think I would preferably fix it between renders using a secure fixing method. I have also not found a bead that can be easily bent to form the oval shape.

Many thanks in advance

[Tony McC]

Rendering really isn't my thing - I always subbed it out or got one of the brickies to do it for me as I hated it with a passion. In 30-odd years on site, and I'll bet I never rendered more than 100m² in all that time.

Bonding - use PVA with the scratch coat. If you have an exceptionally smooth face on the bwk, score it with the nangle grinder or cut-off saw.

Beading - fixed before you do anything else, and held in place with masonry nails or BZP screws'n'plugs. When it comes to bending the bead, you have to 'nick' it with a hacksaw, a technique known (in some parts, at least) as "kerfing".

Sorry, but even though you've never done it before, you're probably better at rendering than I am! :p

[stuartduguid]

This is probably a bit late as you may well have completed it by know. If it went well then congrats if not then this may help next time. As mentioned score and/or use pva for the key. Also, make sure the joints are well raked out. Try pvc bead, it bends far better than metal. To fix the bead, i have used gripfill to good effect as it gives you good time to get it in position. However, if you use this between coats it may not stick very well to damp render. Alternatively use galv nails or dabs of mortar although i've not really found the latter very successfull.

[danensis]

S'funny innit, that you can't get render to stick well to engineering bricks, but the mortar you splatter on the front while you're pointing sticks there for years.