Replacing A Patio Roof

[OneeyedJohn]

Sorry to be flippant Somtham, but for chrissakes you are talking about a roof and some posts adjoined to your house. They are not even laying a concrete floor, now that takes some effort and time.

There's no guarantees in Thailand, no refunds, you pay and take your choice, I don't care if you know where he lives.

You've had good advice.

[Somtham]

Sorry to be flippant Somtham, but for chrissakes you are talking about a roof and some posts adjoined to your house. They are not even laying a concrete floor, now that takes some effort and time.

There's no guarantees in Thailand, no refunds, you pay and take your choice, I don't care if you know where he lives.

You've had good advice.

I've had some very good advice and I appreciate the time people have taken to respond. I will post the spending numbers and progress.

PS - I hope you realize I was just joking on the construction co post.

rgds

[chownah]

I can see that if someone had no building skills and no time to be involved as well and had the extra cash so it wasn't an issue to spend it then they might pay 100,000 baht for the work you describe.......but I wouldn't consider that is was a good price....I'd consider that as a rich farang they had paid alot of money for the work (about double) in exchange for convenience and peace of mind.

I guess the bottom line is what bids can you get and how certain are you that the work will be done nicely. So far in Thailand I have not observed that paying more money gets better work or more honest contractors.

Chownah

P.S. Did some thinking and got back in time to edit. Spanning 8 metres is usually done with steel trusses. This would increase the cost for sure and I have no experience with prices for this kind of work. Spanning 8 metres will also put more weight on the columns that hold up the ends of the trusses...so these should be stouter too and especially their foundations should be bigger. I think that with the 8 metre span I would make a footer under the columns and I might not go with precast but do cast in place...this would push the price up some too......but I still think that 100,000 is high.

If you are thinking of connecting to the house, do you know the size of the footers under the house columns and what the soil conditions are?

Chownah

[Somtham]

I can see that if someone had no building skills and no time to be involved as well and had the extra cash so it wasn't an issue to spend it then they might pay 100,000 baht for the work you describe.......but I wouldn't consider that is was a good price....I'd consider that as a rich farang they had paid alot of money for the work (about double) in exchange for convenience and peace of mind.

I guess the bottom line is what bids can you get and how certain are you that the work will be done nicely. So far in Thailand I have not observed that paying more money gets better work or more honest contractors.

Chownah

P.S. Did some thinking and got back in time to edit. Spanning 8 metres is usually done with steel trusses. This would increase the cost for sure and I have no experience with prices for this kind of work. Spanning 8 metres will also put more weight on the columns that hold up the ends of the trusses...so these should be stouter too and especially their foundations should be bigger. I think that with the 8 metre span I would make a footer under the columns and I might not go with precast but do cast in place...this would push the price up some too......but I still think that 100,000 is high.

If you are thinking of connecting to the house, do you know the size of the footers under the house columns and what the soil conditions are?

Chownah

CN - maybe the earlier post of mine was not clearly written. The contractor did not agree to the 100k price so we settled that I am going to buy all the material myself, pay his labor and then give him 30% of my costs. I figure based on all the numbers posted it will be less than 100K.

P.S. Did some thinking and got back in time to edit. Spanning 8 metres is usually done with steel trusses. This would increase the cost for sure and I have no experience with prices for this kind of work. Spanning 8 metres will also put more weight on the columns that hold up the ends of the trusses...so these should be stouter too and especially their foundations should be bigger. I think that with the 8 metre span I would make a footer under the columns and I might not go with precast but do cast in place...this would push the price up some too......but I still think that 100,000 is high.

If you are thinking of connecting to the house, do you know the size of the footers under the house columns and what the soil conditions are?

Good input on the span. Right now the existing wood header is attached to the end of the house and there are 8 5" x 5" columns supporting the patio roof. 4 lengthwise about 3.5m from the house and another 4 about 7m from the house. The builder wants to use four 9" diameter cement pipes sunk 1m deep and then fill the inside with rebar and concrete when he does the footing.

The soil near the house is hard as rock and I have no idea about the footings. The entire perimiter of the house has concrete poured around it ranging in width from 1 meter on 1 side to 8 meters where the patio is.

rgds

[Nomad97]

From my experience 50K is a very good price for the work you require. However, 100K is not too bad depending on where you live. At the end of the day you have to pay what you have to pay. Good luck and may the Force be with you.

[chownah]

If the wall you'll attach to has no settlement problems and the water table is not high at your location and rain water is all intercepted and channeled away form the house then probably building to the house would work but after construction I would keep an eye on it through at least one or two wet seasons to be ready to do a fix if a problem should arise...but its probably no problem and I guess I'd go with the contractors judgement since you feel that he's capable and experienced.

Having thought some more I'm wondering if the plan is to use 4" steel channels as rafters....that is there will be a stronger beam that goes along the line of the columns which will hold up the 4" channel which will be placed every 1 metre. This seems like a long span for 4" channel but I've not done a steel roof so I have no personal experience. I do have a book of house plans I've borrowed from the Aw Baw Taw (Tambon administrative office) since I'm building a kitchen and I'm using details from the book for the kitchen design. This book shows 3" steel channels to span 2 metres and the longest span in any of the plans in the book I've got is 4.5 metres and they show 6" steel channels for that span. You want to span 8 metres and this is way way more difficult than spanning 4.5 metres. The book I'm borrowing does tend to build everything to a higher standard than most of the construction I've seen so perhaps 4" channels are adequate for 8 metres but it seems light to me....is this an issue where the contractor's judgement should be followed?...I don't know. I might consider buying a couple of pieces of the 4" channel and placing them on some blocks on the ground and weighting them to approximate a roof load and then see how springy they were....all the channel I've seen comes in 6 metre lengths so I guess you would need to weld two metres onto a full piece....hope the welds are good......are you sure the row of columns would be 8 metres from the house or would the row of columns be 6 metres from the house with a 2 metre overhang?......8 metres is quite a long span.......anyway........just so you'll be informed the 6" channel used in the book I borrowed to span 4.5 metres (8 metres is ALOT longer than 4.5 metres when it comes to spanning members) has the following specs which I have translated myself (reasonable chance of accuracy):

150 x 75 x20 millimetres "C" channel with the steel being 3.2 millimetres thick which should yield a weight of 8.01 kilograms per metre.

The weight per metre (along with other shape designations) is a standard practice in specifying steel spanning members.

Hope this helps.

Chownah

[chownah]

Let's consider the asbestos roof tiles. You are going to give the contractor 30% of the cost of the tiles as a profit margin.

If you buy 25 baht tiles and use 3 per sq metre then you will use 300 at a cost of 7500 baht and th 30% for the contractor comes to 2,250 baht. If you buy 60 baht tiles and use 3 per sq metre you will use 300 at a cost of 18,000 baht and the 30% for the ocntractor comes to 5,400 baht. BUT....it takes the same equipment, skill, and time to install either one. So...how do you justify that a different profit should be realized? I can't see any justification for two different profits for the same work and I think that the reason is that using a percentage of material costs across the board is not how reasonable profit margins are calculated. I'm not saying that your 30% is too high or too low...only that using a percentage of material cost is not a rational way to calculate reasonable profits.

Also...if you are paying 30% of all material costs to the contractor then the higher your material costs are the MORE PROFIT the contracator makes and I capitolized "more profit" because this is just about all that some contractors see when they see a worker break a roof tile...or 2.....or 10....or.......it can get really ridiculous in how much can be "accidentally" broken or just "disappear" at a job site when the contractor is getting a percent of material costs as profit. Every 60 baht roof tile broken gives 18 baht of MORE profit from the 30% mark up and if the job lasts longer it also means MORE profit from the markup on the labor!!!!!! SWEET!!!!

I'm not saying that your contractor would be like this....but I'm not saying that your contractor won't be like this either....how could I possibly know?

Perhaps a better way to estimate a profit margin is to figure out how much you think the contractor should make for 5 days work. Should he make 1000 baht per day (twice what the forman makes) or 5000 baht per day (ten times the forman) or 10,000 baht per day? When considering this you should remember that your job is so simple that the contractor's only work is to talk to you now to get your cost as high as possible and then later to collect the money from you....I doubt that the contractor will even need to show up at the job site once construction begins....unless there is a problem which necessitates increasing the costs which will then have to be approved by you. When considering how much per day he should make also consider overhead....office?...doubt it....insurance?...doubt it....wear and tear on equipment?....minimal.....if you are hiring a contractor with alot of overhead then you are hiring the wrong contractor for this job which could be done just as well by a handyman......but of course the contractor won't see it this way.

Chownah

[elkangorito]

Let's consider the asbestos roof tiles.........

Chownah

Is asbestos still used here? I hope, fall the sake of all concerned, that minimal asbestos dust is created during the construction process. Mesothilioma (not sure of spelling) is a nasty thing...especially for any kids who may develop this 20 years down the track after inhaling small quantities of dust.

Better still, never use asbestos products.

[chownah]

There's two kinds of asbestos and the kind used in roofing, sheet cement products, and pipes is not the kind that causes cancer.....of course there are alot of people who say that this is not true and is just industry propoganda to continue its use so I suggest that you go to the internet and read ALOT of links about this topic since you will find both sides of this discussion very well represented on the net.

And....to directly answer your question....yes....asbestos.....its in the vast vast majority of the roofs and drop ceilings in Thailand and in alot of the piping.....but its the good kind.

Enough of off topic. If you want to discuss please make another topic. Its already been discussed in other threads....just search for "asbestos".

Chownah

[Somtham]

I've had some very good advice and I appreciate the time people have taken to respond. I will post the spending numbers and progress.

So here's what the roof cost me. Covered area is 140 sq meters.

Cement, gravel, sand 6,850

Rebar and wire 7,265

Steel 46,295

Labor (780 man hours) 22,100

Tiles and clips 20,740

Contractor 27,913

Paint 1,120

Misc 939

Total B133,221

rgds