Structural Engineer

[JesseFrank]

I have some issues with my house which I like to see solved and have been advised to engage a structural engineer to find the cause and solution to the problem.

I know in Thailand everyone is an engineer, but where do i find a real one ?

[Crossy]

You local ampur planning office could be a good place to start. Ours certainly has an architect on the books who has the rights to sign off on construction plans.

Hope it's nothing too serious.

Do you have the construction drawings that the contractor used? They would be a good place to start.

[JesseFrank]

You local ampur planning office could be a good place to start. Ours certainly has an architect on the books who has the rights to sign off on construction plans.

Hope it's nothing too serious.

Do you have the construction drawings that the contractor used? They would be a good place to start.

The drawings were provided by the orbotor as part of the requirement to obtain a building license

The problem is that the roof construction makes noises during expanding and contracting, previously causing some cracks in walls where they join the columns. I have been told that this probably isn't the roof only but a result of the whole construction (roof and concrete) expanding at different rates.

A roof constructor quoted me 350.000 Baht to building a complete new roof, since fixing could not guarantee the noises to disappear.

A foreign concrete constructor told me that building a new roof may not be the solution.

So how serious this issue should be considered ? Could this lead to a failure of the construction or should this rather been seen as an inconvenience ?

I heard using the term Baan laem, or something like that, but have actually no idea what that mean and if it even is related.

Edited July 21, 2014 by JesseFrank

[eyecatcher]

JF any chance of a photo showing your wall column cracks and also what is it on the roof that is expanding and contracting.

It does sound unusual and roof coverings will move but rare that the construction would.

Outside walls abutting columns and around windows common, rendered walls even more so.

[JesseFrank]

JF any chance of a photo showing your wall column cracks and also what is it on the roof that is expanding and contracting.

It does sound unusual and roof coverings will move but rare that the construction would.

Outside walls abutting columns and around windows common, rendered walls even more so.

I would think it is the steel structure that expands when heating up and contracts when cooling down. It is a fact that the events happen when it reaches a certain temperature, and in addition there must be a significant difference between the minimum and maximum difference of that day to make it happen. The roof structure is welded on the columns of course. I may also add that I have roof overhangs from 1 meter to 1.30 meter on some places which have no support.

The pictures show the cracks, at a side of the house where I have a roof overhang of 1 meter over a length of 17 meter , additional a galvanized rain gutter hangs at the roof.

The rain gutters make a horrendous noise when heating up and cooling down, but I have heard that it is common.

It are not the columns that crack, but just beside the column.

[weegee]

Not too much of a problem and can be fxed....not new roof!!!!!

P.S. computer here no good.....

[JesseFrank]

Not too much of a problem and can be fxed....not new roof!!!!!

P.S. computer here no good.....

When will you come over Weegee ?

My computer is fine.

[eyecatcher]

JF, ok, I understand your concern. I have seen the pictures and your interpretation of what happens.

I want to alleviate your concern.

As you have mentioned more than once the problem is expansion and contraction.

I doubt very much that a roof structure that is not in direct sunlight or frost is likely to move through expansion, the roof covering takes the brunt of this and if you have tiles then even better they have their own expansion joints built in.

Aluminium gutters, yes, even in the cold climes of the uk, one day of sun will create the most unusual noises in a pvc gutter.

its not a problem and certainly not structural.

The render cracking, common as chips. What you have is concrete column and in between a rendered brick panels the bricks will not expand a great deal because the render is taking the heat. the outer skin is actually expanding at 10mm per 10m of wall but because they don't build in butyl expansion joints ,ideally adjacent the columns the render had to go somewhere.

As a result it de bonds from the brick and in some cases blows off......exactly as your photo shows of the missing slip bricks.

Windows in a long wall do help as the frame is an escape but not ideal.

Its not structural and no detriment to the house other than being unsightly.

If these are isolated cracks you can repair, take out and full with a butyl ruberoid mastic and paint over. Any future expansion will be taken up in your new expansion joint.

Do not fill will a strong mortar, as this will create cracking elsewhere.

If it was my house, I would actually use an angle grinder and take out a 10mm wide vertical joint the height of the render and the depth of the render and full it with the gun mastic, frame sealant type, ADJACENT to the concrete columns.

I am still not convinced through your description that you need to be concerned about any of the roof structure, but if you can elabourate I will try to help.

[JesseFrank]

JF, ok, I understand your concern. I have seen the pictures and your interpretation of what happens.

I want to alleviate your concern.

As you have mentioned more than once the problem is expansion and contraction.

I doubt very much that a roof structure that is not in direct sunlight or frost is likely to move through expansion, the roof covering takes the brunt of this and if you have tiles then even better they have their own expansion joints built in.

Aluminium gutters, yes, even in the cold climes of the uk, one day of sun will create the most unusual noises in a pvc gutter.

its not a problem and certainly not structural.

The render cracking, common as chips. What you have is concrete column and in between a rendered brick panels the bricks will not expand a great deal because the render is taking the heat. the outer skin is actually expanding at 10mm per 10m of wall but because they don't build in butyl expansion joints ,ideally adjacent the columns the render had to go somewhere.

As a result it de bonds from the brick and in some cases blows off......exactly as your photo shows of the missing slip bricks.

Windows in a long wall do help as the frame is an escape but not ideal.

Its not structural and no detriment to the house other than being unsightly.

If these are isolated cracks you can repair, take out and full with a butyl ruberoid mastic and paint over. Any future expansion will be taken up in your new expansion joint.

Do not fill will a strong mortar, as this will create cracking elsewhere.

If it was my house, I would actually use an angle grinder and take out a 10mm wide vertical joint the height of the render and the depth of the render and full it with the gun mastic, frame sealant type, ADJACENT to the concrete columns.

I am still not convinced through your description that you need to be concerned about any of the roof structure, but if you can elabourate I will try to help.

The noise must come from somewhere.

It isn't freezing here but where I live we reach 36° in the shadow in daytime and 25° at the same spot during night. I assume that the roof tiles must reach close to 60-70° or maybe higher during the day and the same 25° during the night. Since I have reflective foil under the battens the heat of the tiles stocks up between the tiles and the steel construction.

I have the noise problem mainly at 2 sides of the house. One side is where the sun comes up, and there I will here from 10am till 12pm, while the roof is heating up, a muted "tok" every 15 -20 minutes. Close after midday this will stop, but return from 7pm till 10pm in the same pattern. I was told by SCG that this might be the twisting of the battens because my rafters are 1 meter between.

The other issue is at the opposite side of the house which has a length of 17 meters and with the master bedroom in the middle. The two columns that had the cracks were front and backside of te room ( both in the long wall ) The removed " bricks" are sand stones and were cracked at the same location as the crack in the wall behind.

There the sound that is quite louder only happens once, at the hottest time of the day and at the coolest time of the night.

The top of the walls have a concrete ring beam on which the steel roof beam lays, and which is welded to the steel sticking out of the columns.

Right side of the room has the roof overhanging and is supported by columms at the end. Left side ( 17 meter length) the roof hangs over 1 meter but has no support over the total length.

When the sound happens it is actually a loud knock which I hear at the top location of the columns. It will happen in the columns right side of the room and within 30 seconds a similar knock in the columns left side of the room.

My idea is that the expansion or contraction of the roof makes it move a little because it isn't equally supported at both sides of the room, and brings it slightly out of balance.

[IMHO]

Possible the noises are caused by the battens are having much higher temp swings than the trusses that support them?

Edited July 21, 2014 by IMHO

[JesseFrank]

Possible the noises are caused by the battens are having much higher temp swings than the trusses that support them?

I think that is what may happen at the side of the house that has the muted sounds for a certain period of the day, but at the other side it looks like some event applies power to the gable end, or however that may be called, on which all the rafters are laying and which is welded to the column reinforcement steel.