cracks in new brickwork

[contrebasse]

I'm having a new garage built. The reinforced footings are in clay, but are quite solid (600x600) given its just supporting a single garage. theres a slab on top of the footings

However, the wall brickwork is now complete, and now all its dried out, I can see that the mortar had shrunk away from the bricks in places, so in effect there's a crack. this also joins up with other cracks in a zigzag pattern over a couple of courses.

I mentioned this to the builder and he said yeah that's normal, all brickwork does that. But I've never seen new mortar cracking like that. Feels to me like the bricky didn't put enough of the sticky stuff in his mud ...

Inside, the engaged piers were built up to ceiling height and tied in with standard brick ties every few courses. But now i notice that there's a crack running down the back of each pier. Builder says its because the pier was built onto the slab, whereas the wall was built onto a course of bricks resting on the footing.

Is this normal? If not, should I ask the builder to fix it? What if he says "thats just normal".

[echnidna]

ask Al

[contrebasse]

that's a bit cryptic, Bob

[echnidna]

Its easier than typing out that ozwinner is the bricklaying guru of these forums and that I recommend that you seek his advice

[ozwinner]

I'm having a new garage built. The reinforced footings are in clay, but are HUGE (600x600) given its just supporting a single garage. theres a slab on top of the footings

600x600 is not huge by any means, but it sounds about normal ( I have gone down 1200mm in clay for foundations) .
Clay is the most reactive ground you can have as it shrinks when dry and expands when wet.

However, the wall brickwork is now complete, and now all its dried out, I can see that the mortar had shrunk away from the bricks in places, so in effect there's a crack. this also joins up with other cracks in a zigzag patter over a couple of courses.

Small hairline cracks can be expected as the sand dries out, it is caused by the clay in the sand drying out, a lot of sand has too much clay in it for my liking.

Zig zag cracks make me think there is another problem, like settlement.

I mentioned this to the builder and he said yeah that's normal, all brickwork does that. But I've never seen new mortar cracking like that. Feels to me like the bricky didn't put enough of the sticky stuff in his mud ...

Test the hardness of the mortar after a few days with a nail, if the mortar scratches really easy then there isnt enough cement in it.
If the nail just scratches the mortar then it is fine.

Inside, the engaged piers were built up to ceiling height and tied in with standard brick ties every few courses. But now i notice that there's a crack running down the back of each pier. Builder says its because the pier was built onto the slab, whereas the wall was built onto a course of bricks resting on the footing.

Correct, you cant build one part of the brickwork on a slab and one part on footings without different movements between the two.
The movement will show up as a crack, but, seeing as how the piers are engaged I dont see too much of a problem apart from the cracked mortar.


Is this normal? If not, should I ask the builder to fix it? What is he says "thats just normal".

Hope this helps.

Al

[Fossil]

It sounds like you don't have too much to worry about, although me typing that probably won't allay all of your fears. The crack up the back of the piers is a normal thing, and doesn't affect the structural integrity of the job at all. The piers are there to give the single skin wall some lateral stability, and as long as they are tied to the main wall, everything is fine, as your builder has stated to you.
The other cracking that you mention, may or may not be normal depending exactly where it is, and what size etc. Has the wall been recently cleaned with high pressure? When the bricks are cleaned, it sometimes looks as if walls are cracking, when a flush mortar joint has been used. Any brickwork done on strip footings... no matter what size they are.. is liable to some seasonal cracking, in the future, as the plastic clay moves with moisture differences. It is the nature of the beast.

I hope you don't mind me asking but.....
Why don't you trust what the builder is saying to you. I have been building for 30 years, and haven't ever lied to a client. I don't know any builders who lie to clients either. It's a very quick way to go broke, as most business comes by word of mouth from satisfied customers.
Was this fellow reccomended to you.
Good luck

[contrebasse]

Well I tested the mortar and it seems OK by your scratch test. It can be scratched away though, its not a strng mix.

The wall has been cleaned and the mortar is flush jointed.

I do trust what my builder says, he's very good, but he didn't do the brickwork. When I see brand new brickwork/mortar cracking after only a few days, it doesn't look right to me. To my laymans mind, if the mortar isn't stuck to the bricks, the cracks will let in moisture and the wall won't be integral. I looked at a whole collection of brick walls around the neighbourhood and only the old ones had cracks.

What you have said is reassuring though, so thanks. I'll post a picture tomorrow maybe.

[Metal Head]

I'll post a picture tomorrow maybe.

"A picture is worth a thousand words"

[ozwinner]

Is there any brickies sand left on site?

If there is, get a hand full of damp sand in your hand and squeeze it, is there a lot of sand stuck to your hand?

If so, that could be part of the problem as there may be too much clay in the sand.

I have laid bricks on jobs where the clay content in the sand is in my opinion excessive, the next day after the mortar has set there are cracks around the whole brick.

Al

[contrebasse]

Well, here's some pics

the zigzag crack goes from header course to bottom left

[IMG]http://www.woodworkforums.ubeaut.com.au/attachment.php?attachmentid=42536&stc=1&d=1174717445[/IMG]





If it was old brickwork, I wouldn't be at all concerned, its just cos its brand spanking new!!! Maybe its all OK, it just looks like to me as if some of the bricks aren't stuck to the mortar. Does this matter?

Well the sand test does leave some sand on my hands, so it could be a clay thing ... but if it WAS, what if anything could/should be done?

Also - I didn't ask for flush joints, the DA said clean, pointed finish and I was expecting ironed joints. But when i arrived home late i didn't see it, and in the morning the mortar had set and it was too late to do anything. Is there any technique for getting a nicer joint AFTER the event? Other than scraping it all out and completely repointing?

Matthew

[ozwinner]

Well, here's some pics

The pics didnt load.





If it was old brickwork, I wouldn't be at all concerned, its just cos its brand spanking new!!! Maybe its all OK, it just looks like to me as if some of the bricks aren't stuck to the mortar. Does this matter?

As a whole wall, no.

Well the sand test does leave some sand on my hands, so it could be a clay thing ... but if it WAS, what if anything could/should be done?

Too late to do anything once its up, apart from the obvious.
"Some" sand doesnt indicate too much clay.

Also - I didn't ask for flush joints, the DA said clean, pointed finish and I was expecting ironed joints. But when i arrived home late i didn't see it, and in the morning the mortar had set and it was too late to do anything. Is there any technique for getting a nicer joint AFTER the event? Other than scraping it all out and completely repointing?

No, your stuck with it once set.

If the documentation states Pointed, which is totally different from Ironed, then Im sure its up to the builder to rectify the problem.

Matthew

Al

[contrebasse]

Ok, so for a newby, what is the difference tween pointed and ironed?

[ozwinner]

Ok, so for a newby, what is the difference tween pointed and ironed?

Pointed is done with a small pointing trowel, jointing is done with a round metal rod, also called ironed.

Al

[contrebasse]

but pointing is not, I am presuming, a finish flush with the brick?

[ozwinner]

but pointing is not, I am presuming, a finish flush with the brick?

A finish flush with the brickwork can be Pointed or brushed.
Have a look here, does the finish look like the picture?
Thats a cut flush and/or brushed finish, sorry I havent got a picture on the site of Jointed or Pointed as yet.

Al