New roof advice

[simoh1490]

Just now, grollies said:

OK, but I really like our vented soffit batten and wooden facia board .

 

 

As do I. 

[grollies]

Just now, simoh1490 said:

As do I. 

You're a nice bloke.

[simoh1490]

6 minutes ago, grollies said:

You're a nice bloke.

I'm spoken for. 

[grollies]

3 minutes ago, simoh1490 said:

I'm spoken for. 

555

[Hutch68]

Sheryl have you thought about a thatched roof? Would fit in nicely with the style of your house.
You can't beat a good thatch!


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[Sheryl]

 

OK, if it is possible to just cut away .6 widths of the existing eaves boards and put in the pre-vented ones, that's fine.

 

And no eave flashings, just the plastic bird thingies it shall be. I am still working on those. I was able to get a picture and together with the Thai names folks here so kindly provided I now have people understanding what it is I am asking for...just still haven't found it. Home Pro emphatically mai mee. Another large home supply shop usually has, but currently mout. Two smaller home supply shops that sell roofing, also mai mee.  The two Colorbond suppliers I am currently talking to, also mai mee but I am not certain they knew what it was I meant so I will re-visit that discussion armed with with pictures. As I understand it the stuff has to fit the profile of the roofing so even if I finally track down a place that has it, it might not fit for colorbond. Anyhow I keep trying.

 

Now a new worry that came to me as I was out doing my evening brisk walk  and went by the front of the house:

 

As I have mentioned it is a very unusual roof design (and not in a good way - a design flaw with a retrofitted solution). There are 3 huge valleys where multiple roofs come together, see satellite view

 

 

 

I had really horrible problems at first - the term "leak" does not capture what went on, it really did look just like the final indoor scenes in Titanic, minus the evening clothes. Whole nights with myself and a squadron of neighbors frantically bailing out as massive sheets of water torrentially  poured down inside. (destroying ceilings, of course). Multiple, multiple repair attempts during which I went through every so-called roofer in the district (there is a reason I now bring them in from Cambodia...). Finally the large metal things you see below were installed along with I think cement and tons of silicone all round them. I am not sure if one would call them gutters or flashing, as you can see the sides are raised up, it doesn't lie flat so I have been calling them gutters and presumably there is some sort of flashing beneath. These had to be custom made.

 

 

They worked...and I have a deep seated horror of their every being removed....and their removal will not be easy as  there is cement all around them, at the time put in, the sole priority was ensuring no water would make its way under them. 

 

I realize their removal now is probably inevitable, in order to properly affix the new roof, but would really like them to then be replaced exactly where they are afterwards,  re-cemented/siliconed all round, because no matter what the roofers may say, valley flashings alone will not be enough with the sheer volume of water and depth of these valleys.

 

But I seem to remember hearing something to the effect that Colorbond cannot be in contact with other types of metal? Anyone know about that?

 

 

[simoh1490]

As they say.....this is a horse of a different colour!

 

I shall need some time to study what you've posted, if you can get higher resolution pictures from different angles that would help enormously, it's not clear yet from the google earth picture what the roof shapes are.

 

But as a guiding principle, the concept of putting on a new steel roof and all that entails, AND reinstating a jury-rigged solution for a specific historical problem that involves additional steel and cement.......that is not going to work in any shape or form.

 

I will post my thoughts on all of this in the morning.

[Apiwan2]

Thanks, Simoh.
 
I understand the weight aspect and will be weighing the old tiles and measuring the beams etc.
 
I'm a little confused by the term "insulate" because to me that means keeping temperature in (which I do not want, obviously) , but I gather from what you are saying that insulation can also serve as a reflector against radiant heat? What type of insulation do I need for that?
 
And just how quiet will steel roofing be with insulation? What I currently have is completely quiet -- I don't hear the rain on the roof at all --  and I really don't want to switch to something that is noisier.
 
Any reason why you don't recommend to replace with other  fibro cement panels or similar weight?
 
Lastly, do you know what steel sheets are called in Thai, any brand names and where I might find them?  I don't think they can be found where I live so would likely have to come to Bangkok.
 
Thanks!

The steel sheets are called , wait for it

" metal sheet " I kid you not.

They now come with insulation on the back looks like foil.

But still noisy when it rains.

My house has similar to what you have now just replaced 3 tiles at 80 Baht each

You can also get see through plastic to let light in .






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[simoh1490]

OK got it, forget the pictures, two valleys being fed by five flat surfaces, let me dwell on this.

[simoh1490]

My guess is, from the pictures you've provided, the house was originally a U shape, at some point an addition was made to infill the U hence the smaller shorter ridge in the middle - is that correct?

 

Rainwater disbursement and guttering under the original design would have been simple, lots of flat surfaces all emptying onto the ground. But the new addition meant that several surfaces converged into two valleys, these became overwhelmed by the increased water flow and any guttering couldn't handle the increased flow? Your manufactured jury-rigged solution involving steel and cement, circumvents the rainwater guttering and simply shoots the flow of water out in front of the house and those are the protruding pieces of steel we see in the photograph - is that correct?

 

If the previous question/para is correct, are there additional cement and steel works that we can't see to the valleys either side of the middle ridge that were undertaken at the tme the temporary fix was made? If so, can you describe them? My guess is there is and that's where the flooding occurred, correct?

[carlyai]

From your house pic., those valleys are going to be handling a lot of water, and like I said before my original valley flashing could not handle the water and overflowed the sides into the house.
I saw a picture posted before with different shapes of flashing and I think the side wings were only about 15 cm each. I don't think that's enough.
I think you should go for the biggest valley flashing you can possibly fit.

I'll try and find my archived house construction photos, somewhere...so you can see what I mean.

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[Sheryl]

Yes. The original design had 3 roofs - 2 on either side and one in the middle but the middle one only on the back half of the house, so indeed, a sort of U shape. . The idea was for the middle area in front to be an open porch. This was a terrible idea  - it is always either raining or blazing hot there so the space is unusable without a roof, and even a roof alone is insufficient  because it faces south and all the rain blows straight in with a venegance from there (it just might have been workable had it faced north). So I had that originally open area  enclosed - initially with a flat roof (the enclosure was all plexiglass, so as to preserve the porch-like idea in terms of outdoor view. ) That leaked like a sieve, turns out flat roofs are simply impossible in this area , much less flat roofs with 3 pitched roofs leading to them. So an additional roof was retro-fitted atop this middle front area.  That in turn led to massive leaks from the valleys. The jerry-rigged solution was these huge steel whatever you call them that you can see jutting out, and yes, they shoot water straight out (I have large water jars strategically placed right under them, in fact that -- filtered -- is where i get my drinking water).  I wouldn't say that it bypasses the gutters because there aren't any gutters actually, if by gutters you mean ones that go along the eaves.

 

This middle roof creates actually 3 valleys - the ones on either side  and then one behind it where it meets the original middle roof -the valleys form an "M" shape.  I have not directly seen what is in the mid part of the M but my worker tells me it is similar to the large metal gutter things you see on either side of the front ridge but no cement,. he will climb up and photograph tomorrow. As to where the leak was - it was all coming through into the area under the middle ridge in the front of the house but I can't really say if more from the back or the side valleys

[Sheryl]

2 minutes ago, carlyai said:

From your house pic., those valleys are going to be handling a lot of water, and like I said before my original valley flashing could not handle the water and overflowed the sides into the house.
I saw a picture posted before with different shapes of flashing and I think the side wings were only about 15 cm each. I don't think that's enough.
I think you should go for the biggest valley flashing you can possibly fit.

I'll try and find my archived house construction photos, somewhere...so you can see what I mean.

Sent from my SM-J700F using Tapatalk
 

Yes, please do, sounds exactly like my situation.

 

A lot of water doesn't begin to capture it - I am directly on the south side of Khao Yai and all the water that never makes it to Issan drops right where I am.  So much rain can come down in so short a time that the run off from just one of these valleys can completely fill up a large water cistern (the big round ones about 2 meters high) in half an hour.

 

This is why I have been so anxious to have the supplier actually come and see the roof.  It is not a conventional situation.

 

 

[scorecard]

2 hours ago, Sheryl said:

 

OK, if it is possible to just cut away .6 widths of the existing eaves boards and put in the pre-vented ones, that's fine.

 

And no eave flashings, just the plastic bird thingies it shall be. I am still working on those. I was able to get a picture and together with the Thai names folks here so kindly provided I now have people understanding what it is I am asking for...just still haven't found it. Home Pro emphatically mai mee. Another large home supply shop usually has, but currently mout. Two smaller home supply shops that sell roofing, also mai mee.  The two Colorbond suppliers I am currently talking to, also mai mee but I am not certain they knew what it was I meant so I will re-visit that discussion armed with with pictures. As I understand it the stuff has to fit the profile of the roofing so even if I finally track down a place that has it, it might not fit for colorbond. Anyhow I keep trying.

 

Now a new worry that came to me as I was out doing my evening brisk walk  and went by the front of the house:

 

As I have mentioned it is a very unusual roof design (and not in a good way - a design flaw with a retrofitted solution). There are 3 huge valleys where multiple roofs come together, see satellite view

 

 

 

I had really horrible problems at first - the term "leak" does not capture what went on, it really did look just like the final indoor scenes in Titanic, minus the evening clothes. Whole nights with myself and a squadron of neighbors frantically bailing out as massive sheets of water torrentially  poured down inside. (destroying ceilings, of course). Multiple, multiple repair attempts during which I went through every so-called roofer in the district (there is a reason I now bring them in from Cambodia...). Finally the large metal things you see below were installed along with I think cement and tons of silicone all round them. I am not sure if one would call them gutters or flashing, as you can see the sides are raised up, it doesn't lie flat so I have been calling them gutters and presumably there is some sort of flashing beneath. These had to be custom made.

 

 

They worked...and I have a deep seated horror of their every being removed....and their removal will not be easy as  there is cement all around them, at the time put in, the sole priority was ensuring no water would make its way under them. 

 

I realize their removal now is probably inevitable, in order to properly affix the new roof, but would really like them to then be replaced exactly where they are afterwards,  re-cemented/siliconed all round, because no matter what the roofers may say, valley flashings alone will not be enough with the sheer volume of water and depth of these valleys.

 

But I seem to remember hearing something to the effect that Colorbond cannot be in contact with other types of metal? Anyone know about that?

 

 

 

Our colorbond sits on steel framing and the contractor we used (used him several times for different things, every time happy with his work) is quite professional and thorough, he discusses everything before or during the work, I'm sure he would have mentioned this point if there was any issue.

[Kwasaki]

5 hours ago, Sheryl said:

But I seem to remember hearing something to the effect that Colorbond cannot be in contact with other types of metal? Anyone know about that?

Yes it's called  "isolation" usually carried out buy using coats of paint or isolation tape especially where aluminium contacts galvanized steel or plain steel.which basically like electrical rolls of tape but 50mm & 75mm etc in width.

 

Trying get a closer look of your roof unusual is an under statement but l'm not surprised.

 

If the protruding part of the valley gutter are that size all the way along they are not adequate, larger up-roof sides are require.

 

Edited November 5, 2017 by Kwasaki

[Kwasaki]

5 hours ago, simoh1490 said:

OK got it, forget the pictures, two valleys being fed by five flat surfaces, let me dwell on this.

Where has that been said the satellite picture is well, hazy looked like 2 gables at one elevation and 3 gables on an opposite elevation,  with an intermediate ridged roof which runs midway between 2 outside ridged roofs.

More information is required anyone got a drone that can take aerial pixs. 

[Kwasaki]

A 3mm thick galvanized valley gutter of any use should be like this and when the run is finished at roof end it shape changes to whats called an overflow chute.

[chickenslegs]

Coming in very late to this topic, but I would have recommended that you at least consider spray foam insulation under your existing roof.

 

Applied correctly, the foam will completely eradicate any leaks and will provide heat insulation. Existing tiles/panels are stabilised by the foam (provided that they are in reasonable condition - no massive cracks or holes) and the additional weight is not excessive.

 

I don't know how the cost compares with re-tiling your whole roof. In my case the cost would have been about the same - around 500 Baht per square metre.

 

Re-tiling my roof would not guarantee no more leaks - so I plumped for the foam. No regrets so far

[simoh1490]

I've slept on it!

 

I agree with Kwasaki, the design  of the new centre roof has not been well thought through, the arrangement may work well in the dry but as you've found out it is severely constrained when it rains. The two valleys that you've extended out over the front of the house collect rainwater from the entire roof so it was inevitable it would flood, but it's what it is so the question is how to handle it going forward.

 

It would be really good to get some more detailed photographs and drone pictures would be excellent, that however may not be possible, worst case is that we have to try and imagine what is happening rather than confirm it by hard evidence and that's a risk.

 

You called those valleys like a letter M, in fact they are two side by side letter Y's where one branch of the upper part of the Y is longer, they divide the water from the entire roof between them. That seems to mean that the shape and size of the valley flashings is all important, they probably need to be wider and more pronounced in their shape than you would ordinarily see - the area of the valley which is critical is the lower stem of each letter Y. I guess what you did to prevent the flooding was not only to extend the valley out over the front of the house but also used cement on the edges of the valleys, building walls on each side of them so that the water doesn't overflow?

 

If all of the above is true, your first project once the old roof has been stripped off, is to construct new valleys in a very robust fashion and that's probably a mini project in its' own right, that will eliminate the need for the concrete walls that were built on the flashing to prevent overflow (which would fail over time anyway). The flashing should be as Kwasaki has shown above, deeper, wider and have a lip on the left and the right (to replace the cement), when finished the new roof can be laid over the top of them. I can't see that there's an alternative since there's no ather way to route the rain water nor to intercept it before it reaches those two important valleys.

 

Edited November 5, 2017 by simoh1490

[carlyai]

A 3mm thick galvanized valley gutter of any use should be like this and when the run is finished at roof end it shape changes to whats called an overflow chute.

Yes, that's like I ended up with on the second attempt....big wings....that was my trouble with the first valley flashing, the wings weren't wide enough....looking for my archived pics...filed somewhere safe and can't find them. [emoji21]

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[carlyai]

Coming in very late to this topic, but I would have recommended that you at least consider spray foam insulation under your existing roof.
 
Applied correctly, the foam will completely eradicate any leaks and will provide heat insulation. Existing tiles/panels are stabilised by the foam (provided that they are in reasonable condition - no massive cracks or holes) and the additional weight is not excessive.
 
I don't know how the cost compares with re-tiling your whole roof. In my case the cost would have been about the same - around 500 Baht per square metre.
 
Re-tiling my roof would not guarantee no more leaks - so I plumped for the foam. No regrets so far

Respectfully, In this case and location, I think spray foam is not the way to go and I think what the plan is now is a good plan.

I had the house in Pattaya sprayed a good few years ago, and it is not cheap, so for up country the cost would be heaps, I think.

For the Pattaya house it was the right choice as used the old tiled roof (house about as old as Cheryl's), plus new for extension. And you can't get the tiles off (very difficult), good to stop the Pattaya thieves breaking in via the roof.

I think the wrong choice for up country, and with her tricky roof, if you did get some water leaks, you couldn't get the roof off.

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[Sheryl]

Colorbond does not recommend spray foam and will nto guarnatee product if it is used (might damage the steel).

 

Worker went up the ladder and now have good pix, below shows views from front to back and back to front. It is actually sort of 2 L shapes with the legs of the L facing each other but not meeting. Looking at this I can fully understand why all the leaking and cannot understand why, back when it happened,  more than 5 contractors in a row could not diagnose the problem

 

The valley gutter/flashing (still not sure which term is correct?) now in place was custom made. I'll measure its width.

 

[simoh1490]

Thanks for that Sheryl.

 

I stand behind what I wrote previously, all the initial effort needs to go into fabricating those valley flashings, making the wings much wider than usual and bringing them up the sides of the peaks by about a foot or so - they will be entirely custom, there's nothing off the shelf about that what so ever. Making sure they are fixed at a steep enough angle will also be important in order to make sure the water evacuates that channel quickly rather than being allowed to love slowly off the roof. It's easy enough work to do for someone who is handy, the rolls of sheet steel are also very inexpensive and readily available.

[wayned]

35 minutes ago, simoh1490 said:

Thanks for that Sheryl.

 

I stand behind what I wrote previously, all the initial effort needs to go into fabricating those valley flashings, making the wings much wider than usual and bringing them up the sides of the peaks by about a foot or so - they will be entirely custom, there's nothing off the shelf about that what so ever. Making sure they are fixed at a steep enough angle will also be important in order to make sure the water evacuates that channel quickly rather than being allowed to love slowly off the roof. It's easy enough work to do for someone who is handy, the rolls of sheet steel are also very inexpensive and readily available.

I would also add that they should be fabricated using thicker galvanized metal than is on the rolls and used for normal flashing.  They need to be made to outlast the roof as replacing them at a later date will be a big chore.  I would also recommend that they each drain into a large downspout.  There's a picture in he document that I attached that shows the downspouts used in a similar situation, but I don't like the design of the flashing as it does not travel up under the flashing .

[Sheryl]

OK, thanks. I received a reply also from Bluescope as follows:

 

"I think it is called flashing named Hip Capping, see in the picture No.8
It is used to drain the rain for 2 roof connecting edge. This Hip Capping you can use Alumium or Colorbond.
Yes it said that Colorbond must not direct contact with other metal but this is not direct contact.Direct contact such as you install the copper lighting rod on the Colorbond."

 

So it seems the valley flashing/hip capping can be made from colorbond and key thing will be to be sure it is large enough, and if necessary aluminimum gutter similiar to what I have can be laid atop it.

 

The contractor foreman arrived last night and the team and I had a long chat including watching a video of Bluescope installation. They seem familiar with installing metal sheet and also to have a good grasp of what is planned, inclusive of the radiant barrier, insulation and plastic thingies.

 

The main concern that was voiced was how to lay down the insulation on the ceiling floor given that it is a hanging ceiling. How do we accomodate the metal hangers? Even if they disconnect one at a time to get the insulation through (which may cause the ceiling to sag or collapse?), they can't reconnect it without piercing through the insulation. What have others done? I assume I am not the only one with a hanging ceiling.?

 

 

[Kwasaki]

3 hours ago, simoh1490 said:

what it is so the question is how to handle it going forward.

 

drone pictures would be excellent, that however may not be possible,

 

You called those valleys like a letter M, in fact they are two side by side letter Y's where one branch of the upper part of the Y is longer, they divide the water from the entire roof between them. That seems to mean that the shape and size of the valley flashing's is all important, they probably need to be wider and more pronounced in their shape than you would ordinarily see - the area of the valley which is critical is the lower stem of each letter Y. I guess what you did to prevent the flooding was not only to extend the valley out over the front of the house but also used cement on the edges of the valleys, building walls on each side of them so that the water doesn't overflow?

No-one about who can help with a drone maybe give NASA a call. 

 

Anyway serious now.

The way forward will be difficult someone with good roofing experience will need to closely supervise the works.

 

Don't understand your terminology of 'M'  & 'Y'.

From hazed observation there 2 runs of horizontal wide valley gutters and 8 slopping gable valley gutters.

 

The roof plan is as this hazed guess from aerial view and pix from page 8 & 13, the middle picture page 8 however creates a mystery showing hip roof junctions.

Pix of that where contact is made with roofs would make roof plan clearer.

I'm off for a pint. 

 

[wayned]

My hanging ceiling uses 60cm square panels.  The insulation that I used came in rolls that were 60cm wide so they fit fairly well between the wires without removing any.  There are a few places were the insulation was cut to make it fit properly.  I have 225 square meters of hanging ceiling  and all of the insulation was installed this way.

[Sheryl]

9 minutes ago, Kwasaki said:

 

 

 

..From hazed observation there 2 runs of horizontal wide valley gutters and 8 slopping gable valley gutters.

 

The roof plan is as this hazed guess from aerial view and pix from page 8 & 13, the middle picture page 8 however creates a mystery showing hip roof junctions.

Pix of that where contact is made with roofs would make roof plan clearer.

 

I'm off for a pint. 

 

Pix are above in post 205. Yes, there here 2 large valley gutters AKA hip cappings (?)

There are no gable gutters

 

A bit early for a pint isn't it ?

[Sheryl]

6 minutes ago, wayned said:

My hanging ceiling uses 60cm square panels.  The insulation that I used came in rolls that were 60cm wide so they fit fairly well between the wires without removing any.  There are a few places were the insulation was cut to make it fit properly.  I have 225 square meters of hanging ceiling  and all of the insulation was installed this way.

Mine are much larger ceiling boards (giemsa type things,  about 2.4 m x 1.2 meters) not small panels but anyway that's not the issue, it is the spacing of the hangers . So the idea is just to squeeze between the hangers where possible and otherwise to cut the insulation?

[simoh1490]

1 hour ago, Sheryl said:

Mine are much larger ceiling boards (giemsa type things,  about 2.4 m x 1.2 meters) not small panels but anyway that's not the issue, it is the spacing of the hangers . So the idea is just to squeeze between the hangers where possible and otherwise to cut the insulation?

You have to do a combination of those things, including removing one or two strategically placed hangers. In most cases the insulation will fit between the beams but where a wire does get in the way, either bend the insulation around it, cut the insulation and then retape the cut afterwards or remove the hanger entirely. And all that has to be done whilst balancing on a two inch steel beam, it's great fun!