Getting It Done Properly This Time

[sonicdragon]

OK

So, after 2 failed (subsiding) kitchen extensions, I am resolved to have it done "properly" this time so we will demolish the last one soon and start again. The last advice we had was that the previous contractor did not pile down to the specified depth AND also used thinner rebar in the floor than was specified. Anyway, my plan this time is to find a reputable contractor to design and build the extension, AND to have the plans scrutinised, and changed if necessary, by a qualified structural engineer, AND to buy the specified rebar and piles ourselves (in fact to buy all the materials rather than let the contractor do so) AND to have periodic inspections by the engineer to check that the work is being carried out according to the specs.

Does this seem like a sensible/realistic plan ? It seems like overkill for such a small project, to me, but I just don't want another disaster (third time lucky I hope!). Does anyone have any other/further advice. Can anyone recommend a suitable qualified engineer who would work on such a small project ?

Thanks in advance

SD

[ProThaiExpat]

Do you know the depth of your "footings" on your house. If you built your house, you should duplicate the "footings" for any addition. The square concrete "foot" for your pilings should be on bedrock or dense soil. Determining how deep you must go for the bedrock or supporting soil is the key issue to ensure no subsidence. Most competent builders can do it, but you will have to to inspect the hole dug for the footings and the pilings to ensure they have hit bedrock or soil sufficient to carry the load.

[sonicdragon]

Do you know the depth of your "footings" on your house. If you built your house, you should duplicate the "footings" for any addition. The square concrete "foot" for your pilings should be on bedrock or dense soil. Determining how deep you must go for the bedrock or supporting soil is the key issue to ensure no subsidence. Most competent builders can do it, but you will have to to inspect the hole dug for the footings and the pilings to ensure they have hit bedrock or soil sufficient to carry the load.

We didn't build the house but I know it is on 24m piles. One complicating factor is that we have small lake near the back of the house and this affects the subsoil where the extension is the be.

[soundman]

One way of employing an engineer that has a good idea of local conditions is going down to the area's thesabahn or O.B.T. administrative offices & speaking to the duty engineer there. For a very reasonable fee he will usually be happy to run up a set of plans in his own time & for another fee oversee the construction for you.

I used the thesabahn engineer to draw up the plans for my factory & in doing so passed all the local planning regulations & checks without any dramas. All for only 10,000B. Bargain as far as I was concerned.

Hope this is some help.

Soundman.

[londonthai]

We didn't build the house but I know it is on 24m piles. One complicating factor is that we have small lake near the back of the house and this affects the subsoil where the extension is the be.

24m piles is more like for a skyscrapper - my house is build on 6m deep piles in the very muddy ground, with a big khlong next to it, with just a few meters over the sea level. I think you need to find other ways for fundation other than piles. It's interesting that's only the extension and not the house which is sinking.

[sonicdragon]

We didn't build the house but I know it is on 24m piles. One complicating factor is that we have small lake near the back of the house and this affects the subsoil where the extension is the be.

24m piles is more like for a skyscrapper - my house is build on 6m deep piles in the very muddy ground, with a big khlong next to it, with just a few meters over the sea level. I think you need to find other ways for fundation other than piles. It's interesting that's only the extension and not the house which is sinking.

Skyscrapers have significnty deeper than 24m foundations. In Hong Kong where I spend a lot of time they pile down 50m or more for large buildings.

The house is on 24m piles and is not sinking. The first extension was on 12m piles and subsided. The second extension was supposed to be on 24m piles but as far as we understand the contractor cut corners and only used 12m piles, and it is subsiding (so far 65cm in 2 years)

I am no engineer, that's why I was suggesting that i should employ one (which is what I am asking for opinions about here), but perhaps 6m below your house is bedrock. 6m below ours is mud.

[sonicdragon]

One way of employing an engineer that has a good idea of local conditions is going down to the area's thesabahn or O.B.T. administrative offices & speaking to the duty engineer there. For a very reasonable fee he will usually be happy to run up a set of plans in his own time & for another fee oversee the construction for you.

I used the thesabahn engineer to draw up the plans for my factory & in doing so passed all the local planning regulations & checks without any dramas. All for only 10,000B. Bargain as far as I was concerned.

Hope this is some help.

Soundman.

Thank you ! I will check that out ! Do you know how to write "OBT office" in thai ?

[soundman]

Thank you ! I will check that out ! Do you know how to write "OBT office" in thai ?

เทศบาล - thesabahn

อ.บ.ต. - O.B.T.

Cheers.

[ignis]

One of the main problems as I see it……… They do not tie into the main house, so you have a building with 3 sides + a slopping roof…… as it is slopping roof most of the weight of the roof is on the outside wall..

Now looking at how most kitchens appear to subside and leave the main house, I built mine different, I had a steel man come and build a Steel frame and roof 6m x 3m, on the house side the steel is bolted into the ring beam of the house every 1 m.. I then myself did the rest, [used wood windows and door] building the wall I used the Thermo block, which is very light 60x20x7 and you use glue.. As these block are large [cut with a normal saw] + glued you have a perfect finish and so just need to skim over with plaster = far far lighter then the Thai way of brick….. To look at from inside or out it looks no different than the main house

That was just over 3 years ago and there has been NO movement, no cracks anywhere…

2 houses away + across the road had the normal Thai type build, both have plastic sheeting taped to the house at this moment because the gap at the top is so wide, both had yet another repair done last March

[sonicdragon]

Thank you ! I will check that out ! Do you know how to write "OBT office" in thai ?

เทศบาล - thesabahn

อ.บ.ต. - O.B.T.

Cheers.

Thank you

[sonicdragon]

One of the main problems as I see it……… They do not tie into the main house, so you have a building with 3 sides + a slopping roof…… as it is slopping roof most of the weight of the roof is on the outside wall..

Now looking at how most kitchens appear to subside and leave the main house, I built mine different, I had a steel man come and build a Steel frame and roof 6m x 3m, on the house side the steel is bolted into the ring beam of the house every 1 m.. I then myself did the rest, [used wood windows and door] building the wall I used the Thermo block, which is very light 60x20x7 and you use glue.. As these block are large [cut with a normal saw] + glued you have a perfect finish and so just need to skim over with plaster = far far lighter then the Thai way of brick….. To look at from inside or out it looks no different than the main house

That was just over 3 years ago and there has been NO movement, no cracks anywhere…

2 houses away + across the road had the normal Thai type build, both have plastic sheeting taped to the house at this moment because the gap at the top is so wide, both had yet another repair done last March

Very interesting. But doesn't it mean that the weight of the extension is being (at least partially) supported by the outside wall of the main structure of your house - ie pulling it outwards ? Where exactly is it bolted to the house ? Along the 1st floor concrete beam and down each of the concrete pillars ?

[ignis]

One of the main problems as I see it……… They do not tie into the main house, so you have a building with 3 sides + a slopping roof…… as it is slopping roof most of the weight of the roof is on the outside wall..

Now looking at how most kitchens appear to subside and leave the main house, I built mine different, I had a steel man come and build a Steel frame and roof 6m x 3m, on the house side the steel is bolted into the ring beam of the house every 1 m.. I then myself did the rest, [used wood windows and door] building the wall I used the Thermo block, which is very light 60x20x7 and you use glue.. As these block are large [cut with a normal saw] + glued you have a perfect finish and so just need to skim over with plaster = far far lighter then the Thai way of brick….. To look at from inside or out it looks no different than the main house

That was just over 3 years ago and there has been NO movement, no cracks anywhere…

2 houses away + across the road had the normal Thai type build, both have plastic sheeting taped to the house at this moment because the gap at the top is so wide, both had yet another repair done last March

Very interesting. But doesn't it mean that the weight of the extension is being (at least partially) supported by the outside wall of the main structure of your house - ie pulling it outwards ? NO: The concrete/steel ring beam runs all around the house and the steel is fixed and wired into the down pillars.. Using roof sheets = far less steel needed = much reduced weight .. OK there is a little more noise when it is raining hard. I have a detached house

Where exactly is it bolted to the house ? Along the 1st floor concrete beam and down each of the concrete pillars ?

Yes all along the concrete & steel ring beam and down the 3 pillars