View Full Version : cracks in new brickwork
contrebasse
23rd March 2007, 01:49 PM
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
23rd March 2007, 01:54 PM
ask Al
contrebasse
23rd March 2007, 02:22 PM
that's a bit cryptic, Bob
echnidna
23rd March 2007, 02:29 PM
Its easier than typing out that ozwinner is the bricklaying guru of these forums and that I recommend that you seek his advice
ozwinner
23rd March 2007, 04:27 PM
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
23rd March 2007, 04:32 PM
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
23rd March 2007, 10:20 PM
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
23rd March 2007, 11:34 PM
I'll post a picture tomorrow maybe.
"A picture is worth a thousand words"
ozwinner
24th March 2007, 08:28 AM
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 :doh:
contrebasse
24th March 2007, 11:42 AM
Well, here's some pics
the zigzag crack goes from header course to bottom left
http://www.woodworkforums.ubeaut.com.au/attachment.php?attachmentid=42528&stc=1&d=1174695585http://www.woodworkforums.ubeaut.com.au/attachment.php?attachmentid=42536&stc=1&d=1174717445
http://www.woodworkforums.ubeaut.com.au/attachment.php?attachmentid=42537&stc=1&d=1174717445
http://www.woodworkforums.ubeaut.com.au/attachment.php?attachmentid=42527&stc=1&d=1174695531
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
24th March 2007, 05:00 PM
Well, here's some pics
The pics didnt load.
http://www.woodworkforums.ubeaut.com.au/attachment.php?attachmentid=42528&stc=1&d=1174695585
http://www.woodworkforums.ubeaut.com.au/attachment.php?attachmentid=42527&stc=1&d=1174695531
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
24th March 2007, 05:27 PM
Ok, so for a newby, what is the difference tween pointed and ironed?
ozwinner
24th March 2007, 05:36 PM
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
24th March 2007, 06:27 PM
but pointing is not, I am presuming, a finish flush with the brick?
ozwinner
24th March 2007, 06:37 PM
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 (http://www.brickwork.net.au/images/Flush-cut1.jpg), 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 :)
ozwinner
24th March 2007, 06:44 PM
Just seen your pictures, and what you have there is a cut flush or brushed finish, cheap and nasty.
You seem to have a settlement zig zag crack.
The other cracks on the soldier course are due to excessive pressure used by the brick cleaner on his pressure washer, time and time again Im called back to fix this "problem", when brickwork was washed by hand before the lazy bastards started to us pressure washers I never had this problem.
Al :(
Groggy
24th March 2007, 06:55 PM
I know nothing about brickwork, but that whole job looks shoddy to me. There are gaps in the mortar and the bricks are uneven in two planes.
ozwinner
24th March 2007, 07:06 PM
I know nothing about brickwork, but that whole job looks shoddy to me. There are gaps in the mortar and the bricks are uneven in two planes.
Ok just relooked at the pics as a whole rather than at the cracks, and apart from the acid wash down its the sort of finish I would leave for a render job.
Al :-
Theremin
25th March 2007, 09:33 PM
Is it just me, or are some of these mortar joints a bit thin?
manoftalent
25th March 2007, 09:55 PM
If it is a concern to you on the way it looks, try roughing it over with an old coldchisel to get rid of any excess mortar ...its a little time consuming as in do it by hand not with a hammer ....then use some bag mortar mix from your local hardware shop and tidy it up .....in general time costs money and you pay for what you get ....on a bright note the wall looks solid enough and wont fall down and due to the unseasonal heat we have had it is normal to "see" some shrinkage in new work, you may see hairline cracks ....most of them are external.....really poor work goes all the way to the other side ....check both sides of the work and if your concerned talk to the builder, if still unsatisfied ....then the logical coarse would be to seek a second opinion......if it were me ......I would do as previously suggested and start cleaning, with a mental note to make sure that next time the builder understands what I wanted the final finish to be .....
we all make mistakes .......it how we learn from them that counts.
TARLOX
26th March 2007, 01:45 PM
Is this a join between new and existing brickwork?
contrebasse
26th March 2007, 01:55 PM
No its all new work. I'll think I'll take manoftalents advice and consider any fault that goes right through to be unacceptable. Anything that appears dodgy but does not go through i may complain about but resign myself to fixing myself ...
An interior dividing wall was built by the same tradesmen, and one face looked OK, but the other face was so starved of mortar I could stick my finger in the cracks. i complained about that and they filled the cracks, but not before they observed "it's going to be covered up so its not a problem". Maybe so, but I don't think it takes that much extra effort to ensure there's good mortar coverage.
ozwinner
26th March 2007, 06:38 PM
Is it just me, or are some of these mortar joints a bit thin?
Tolerance for joints is nominal 10mm, + or - 3mm.
Al :)