Bricks cracking? - DIY Chatroom

PaulBob · 10-20-2009, 11:29 AM

Hi all,
I'm finding a problem with the bricks on the first or second row near the ground level around my home.

There are about 20 or more bricks doing the same thing in different spots around the home. The brick face is cracking and flaking off. I have attached a picture of one of them to show what I'm talking about.

What is the cause of this and how to fix it? My home is about 30 years old.

cellophane · 10-20-2009, 12:40 PM

your bricks are spalling. this link has some good information on what causes it - in your case it is probably the lower quality brick. wikipedia explanation of spalling as a mechanic.

basically the brick absorbs too much water and the back pressure from the water causes part of the brick to fall off (or it freezes and expands.) i believe there are some sealants you can get that will slow this down and prevent water from penetrating the brick. you should also make sure that your weeps are clear and you have good drainage behind your brick. spalling can also occur from the inside if moisture in the wall isnt able to drain out.

sdsester · 10-20-2009, 12:45 PM

Quote:

Originally Posted by cellophane

spalling can also occur from the inside if moisture in the wall isnt able to drain out.

And if this is the case, sealing the brick may just compound the problem.

stuart45 · 10-20-2009, 04:55 PM

Spalling often happens at the bottom of the wall as these bricks are often wetter through rain bounce, or water running down the inside face. In the UK now the codes mean that frost resistant bricks have to be used at low level below DPC.
Crptoflorescence sometimes does this to brickwork, and sealing the wall can increase the problem.

PaulBob · 10-20-2009, 05:59 PM

Read the links. Thanks.

A few questions,
1) What are "weeps"
2) How to fix the problem once it happens
3) How to know if sealing it will work?

I just bought some Behr concrete and masonary water-proofing stuff because I poured a cement pad in my backyard and want it to stay looking nice. This stuff I bought is a satin or flat mat finish that is clear so you can barely see it. Should I apply that to the bricks around the bottom 2 rows or so?

Thanks again!
I don't know much about this kind of stuff so I'm glad you guys do.

stuart45 · 10-20-2009, 06:14 PM

Weep holes are open cross joints(head joints) at the bottom of the wall which allow water to escape from inside the cavity. We put them in every 4th brick, nowadays with a plastic or nylon insert.
Siloxane sealant is said to allow the walls to breathe.

itsreallyconc · 10-20-2009, 08:37 PM

silicone siloxane - we use prosoco