making good: part-brick-sized hole in wall

[jkn]

Hi all We have a gap in our outer cavity wall which I want to make good. It was caused when the drain pipes from the newish loo were fed out through the wall. Our fitter never quite finished the job ... you know how it goes...

He knocked out about 3/4 of a brick and there are two 28mm(? - approx) pipes coming out. There is a bit of space at either side of the pipes, if you get me. So I have to make good a couple of spaces, one (nearest an inner corner) about 1.5inch by 3inch, and one about 3 inch by 3 inch. Of course the actual space is irregular.

I'm not very familiar with brickwork and the making good thereof. What are the panel's suggestions as to how to finish this area off? I have an angle grinder and bolster chisel etc., just not necessarily the skills to make the best use of them...

Thanks for any suggestions..

Jon N

[Andy]

Clear out any leftover mortar in the hole with a chisel ( if practicable ). With a bolster chisel strike an appropriate sized lump of brick off a brick that more or less matches what you have. Mix up some mortar, 1:4 cement to soft sand, maybe add a little PVA, but make a somewhat drier mix than if you were going to lay a brick with a trowel.

Slap mortar on bottom of hole and side(s) of brick piece. You might want to add a bit of water to this mix to make it more like normal bricklaying mortar, able to flow a little/hang on to a brick.

Adjust into position without too much fuss.

Take some of the original drier ( not dry ) mortar mix and pack into the space above the new bit of brick using a bit of suitably shaped wood. The reason for the drier mix is that it can be packed without flowing out of the way or down the back of the brick. Keep adding mortar and packing until hole is filled and feels solid.

Repeat on other side of hole as necessary. Copper pipes should not be encased in mortar. Wrap in Denso tape first if you want to cement in the pipes.

Andy.

[Harry Bloomfield]

jkn was thinking very hard :

If the hole was made after the wall was built, it should be possible to fit a full brick by the removal of the part brick still in the wall. This will look better than botching it with another part brick and you can use the removed bit as a sample to find a matching replacement. Measure the size of brick needed, they are not all the same size.

The angle grinder fitted with a stone disk will allow you to grind out the mortar to remove a part brick, or square off the hole ready to be filled. Clean out as much of the old mortar as possible around the hole, find a matching brick and cut to size with the angle grinder if it has to be a part brick. Wedge it tightly in place with wood dowel so it is square, level on the face and with even gaps - so it can't move, but yet you can get the dowel back out. Give the area a good wetting with a water spray. Mix some mortar fill the joints, pushing it sideways to compact it and so it fills the gap all the way to the rear of the brick.

Allow it to set for a while, long enough to be self supporting to allow the removal of the dowel, then fill in the dowel holes and point to match the rest of the brick work.

[jkn]

Thanks Andy & Harry, very useful. I'll let you know how I get on ... once I've re-discovered my Bolster Chisel...

Cheers Jon N