Wall Cracking

[crisp]

Hi,

Hope i have posted this request on the correct forum.

I have a problem with one of my outside walls cracking.

My wife has tried to get a builder/s to repair it. Unfortunately nobody is interested because its a small job & therefore not very profitable job, according to my wife.

Can anybody suggest a builder who whould be willing to undertake the job?

I live in Nonthaburi Province, near Pakret.

Any help would be appreciated

Chris

[bbradsby]

Assume you're talking about plaster veneer cracking - middle of wall, typically over clay brick infill in Thailand - and not structural concrete but you should clarify this important distinction. Also it'd help if you'd post pix to clarify the condition. Are they hairline cracks or something larger that you could put a 10 baht coin into? If the latter, an architect or engineer should look at it quickly. Have you observed crack proliferation? Waterproof-pen mark the ends of cracks and observe any changes, first in 24 hours; then weekly if no change is ID'd in the first 24 hours.

Hairline cracks -in the absence of structural movement - are due to concrete/plaster shrinkage as the material sets over time, and are normal unless the mix was entrained with microfiber reinforcement. Mixtures with more water shrink more, and even a good mix will crack if not properly protected from rapid drying in the sun & wind - the first 48 hours are critical. East & West-facing walls or exposed, horizontal surfaces are most vulnerable.

If you post pix, I can have a better idea of your specific condition & best remedy.

Bruce Bradsby

Edited August 28, 2010 by bbradsby

[crisp]

Assume you're talking about plaster veneer cracking - middle of wall, typically over clay brick infill in Thailand - and not structural concrete but you should clarify this important distinction. Also it'd help if you'd post pix to clarify the condition. Are they hairline cracks or something larger that you could put a 10 baht coin into? If the latter, an architect or engineer should look at it quickly. Have you observed crack proliferation? Waterproof-pen mark the ends of cracks and observe any changes, first in 24 hours; then weekly if no change is ID'd in the first 24 hours.

Hairline cracks -in the absence of structural movement - are due to concrete/plaster shrinkage as the material sets over time, and are normal unless the mix was entrained with microfiber reinforcement. Mixtures with more water shrink more, and even a good mix will crack if not properly protected from rapid drying in the sun & wind - the first 48 hours are critical. East & West-facing walls or exposed, horizontal surfaces are most vulnerable.

If you post pix, I can have a better idea of your specific condition & best remedy.

Bruce Bradsby

Hi Bruce,

Thanks for the reply. i'm not home at the moment, i work abroad & not due back untill October!

I think its a structural problem & quite serious, in that the crack is about 10mm wide at the widest point. it is actually where a garage has been built onto the exsisting house. I suspect its been ground movement that has caused this.

I assume from your reply you are a builder/arcetect as you seem very knowledgable.

I will post a picture when i'm next home.

Thank you again

Chris

[bbradsby]

Hi Bruce,

Thanks for the reply. i'm not home at the moment, i work abroad & not due back untill October!

I think its a structural problem & quite serious, in that the crack is about 10mm wide at the widest point. it is actually where a garage has been built onto the exsisting house. I suspect its been ground movement that has caused this.

I assume from your reply you are a builder/arcetect as you seem very knowledgable.

I will post a picture when i'm next home.

Thank you again

Chris

Sounds like differential settlement - very common here, where the original structure is on concrete piers driven into the fill & aluvium/rice paddy/swamp and is quite stable if done correctly. The additions, well... will await your pix.

-bruce

[sonicdragon]

It's almost certainly differential settlement, as Bruce said. How soon after the garage being built did the crack start to appear ? About 6 months ? Is the crack wider at the top than the bottom ? If so, then basically, what's happening is the footings of the garage next to the house are riding on the foundations of the house and so that end of the garage remain fixed relative to the house, but the other end of the garage is sinking relative to the house, that's why the crack is wider at the top.

There's is very little you can do about it, other than having the garage rebuilt using the same type and similar depth foundations as the main house and even then you can get a similar problem though *much* less pronounced. For a single story extension (garage, kitchen etc) most people don't have proper foundations because of the added cost. The simple solution is just have the gap filled in from time to time. If you've got a false ceiling in the garage then expect to have problems with that too (it will move away from the main structure over time), but this might not become apparent for a year or so. Another problem to look out for is where the roof of the garage meets the main house - depending on how that was done, it might need remedial attention (possibility of collapse). Eventually, you'll probably have to rebuild the garage. We had exactly this problem with a kitchen extension a few years back - eventually it got so bad that we had it rebuilt. It's possible to have proper foundations done in-situ, but it's very expensive - cheaper and much easier just to rebuild.

[crisp]

Hi Bruce,

Thanks for the reply. i'm not home at the moment, i work abroad & not due back untill October!

I think its a structural problem & quite serious, in that the crack is about 10mm wide at the widest point. it is actually where a garage has been built onto the exsisting house. I suspect its been ground movement that has caused this.

I assume from your reply you are a builder/arcetect as you seem very knowledgable.

I will post a picture when i'm next home.

Thank you again

Chris

Sounds like differential settlement - very common here, where the original structure is on concrete piers driven into the fill & aluvium/rice paddy/swamp and is quite stable if done correctly. The additions, well... will await your pix.

-bruce

Hi Bruce,

Got the wife to send me a pic.

Whats your take on it please?

Thank you

Chris

[rgs2001uk]

Try reading the following link for an insight,

[bbradsby]

Need to get the whole wall with the problem crack in the pic to get a better perspective. Also, pix of the floor & ceiling, roof, & exterior wall at the connection between garage & house would help.

But from your thread comments sofar, it would appear to be differential settlement of the addition versus the original structure. Very typical stuff unfortunately around here. Just look at any of the big [Thai or the USoA] 'developer/builder house's slabs poured out back. They just pour a few cm's of concrete on the uncompressed soil, and within a few months it begins to drop away from the house. Of course they know it'll drop away, but they don't care - the house is sold and the layman buyer has no idea 'til it's too late. If it remains only a slab on grade, there's no real harm done. However, add a roof & walls and things can get dicey as the structures move independently of each other.

SonicDragon's right; depending on how the garage roof is framed, there may or may not be a collapse hazard. But, as concrete framing is used so extensively here, you should have it looked at by a local professional unless you have the expertise to analyze the framing systems & load paths. They may recommend disconnecting the garage 'foundation' from the original to remove the hinge point and allow the garage to 'float' & settle evenly, on its own. You may also have to add garage roof supports to supplant where the original structure now supports the garage roof - if in fact it does. Again, a professional such as an architect or structural engineer should review the entire condition and advise on the prudent, least cost solution. It may also just require periodic plaster & forbearance on your part!

Hope this helps,

-bruce

Hi Bruce,

Thanks for the reply. i'm not home at the moment, i work abroad & not due back untill October!

I think its a structural problem & quite serious, in that the crack is about 10mm wide at the widest point. it is actually where a garage has been built onto the exsisting house. I suspect its been ground movement that has caused this.

I assume from your reply you are a builder/arcetect as you seem very knowledgable.

I will post a picture when i'm next home.

Thank you again

Chris

Sounds like differential settlement - very common here, where the original structure is on concrete piers driven into the fill & aluvium/rice paddy/swamp and is quite stable if done correctly. The additions, well... will await your pix.

-bruce

Hi Bruce,

Got the wife to send me a pic.

Whats your take on it please?

Thank you

Chris

[canopy]

The important thing to note is this is not a static thing. Such cracks will grow and more cracks can form. There can even be seasonal movement where cracks open and close a bit during different times of the year. Thus, patching where it is now is a futile effort.

 

Infill walls in Thailand are really easy to redo as you just knock out a segment between posts and re-block it. Redo the wall on a proper base. Use a different builder for sure as the one you had botched the job and is apparently not standing behind his work. And maybe use q-con this time if you aren't already for an added bonus of better thermal insulation.

 

[Crossy]

Guys.

 

This is a thread from 2010. The OP's home is either fixed or has fallen down by now.

 

Probably time to let it rest in peace.

 

EDIT It was also bumped into view by a spammer.

 

[metisdead]

And the spammer who bumped this topic has now been flagged.