Mortar

[John]

I have to replace the coping stones on top of a dwarf walk. The area (of mortar) measures approx 2.4m long by 250mm wide by 20mm deep. A neighbour tells me it is not wise to do any 'bricklaying' in this cold weather. Is he correct or is it an old wives tale? When I have been driving around over the last few days I have seen plenty of housebuilders working. Will it be OK, or is there something I would need to add to the sand and cement mix? I do not mind doing it in the cold but I don't want to redo it again if the bond fails.

Cheers

John

[Andrew Gabriel]

It's not the best time of the year to do this sort of thing. You can get antifreeze to add to mortar mix if you really have to.

The bond at the top of a wall is particularly important, as there aren't tonnes of bricks on top to keep the bricks in place. I would add a small amount of exterior grade (water proof) PVA to the mix to improve the tensile bond strength at the top of an outside wall.

[fred]

In article , John writes

My dad built his own house (many years ago) and wondered why he hardly got any BCO visits while the commercial sites nearby got loads. He asked the BCO who told him he knew that he would make a good job as he was going to live in the finished house with his family but the jobbing brickie wouldn't give a toss as long as he was paid, bit of an unfair generality I think but you get the idea. The particular BCO had a rep for doing the rounds after a night of frost and getting the builders to demolish fresh walls that hadn't been protected from the frost.

So, long story short, Andy's advice is good (as ever).

[somebody]

In message , John writes

Hi,

Your neighbour is generally right.

What no-body wants is the water in the mortar freezing or even 'frosting' overnight. Apparently it can significantly weaken the mortar.

Personally, given the choice, I'd leave it until better weather - but for copings on a dwarf wall... you're not exactly building Docklands! It should be fine.

I'd say both the builder and the neighbour are right but it has come up on this NG in the past, that sometimes people get a little too protective/pedantic over their own works.

Hth

[Steve Walker]

Wouldn't a level surface be better, perhaps with a handrail?