Total price per square meter for a metal roof made with metal roof tiles with insulation underneath?

[medic5678]

I'm building a very similar building as to what you are building Jim.  At this time, we've got the slab poured, the concrete posts in place and the supporting metal up on the roof.  We're getting ready to buy the metal for the roof.   Your post has been enlightening.

 

For the sides, we're planning to use block.  I'm wondering what sort of vapor barrier, exactly where to put it and how to insulate the walls.  What are your plans?

[sometimewoodworker]

4 hours ago, medic5678 said:

 

For the sides, we're planning to use block.  I'm wondering what sort of vapor barrier, exactly where to put it and how to insulate the walls.  What are your plans?

Your questions answered in your other thread are in there

Edited October 12, 2019 by sometimewoodworker

[JimShortz]

On 10/13/2019 at 12:25 AM, medic5678 said:

For the sides, we're planning to use block.  I'm wondering what sort of vapor barrier, exactly where to put it and how to insulate the walls.  What are your plans?

Why would you want to install a vapour barrier? To the best of my knowledge this is not normal for twin block wall homes, but rather for timber framed homes with brick/block cladding. I have an air space only, and eaves that keep the rain largely off the exterior walls anyway.

[cheeryble]

AFAIK our new house with single AAC block doesn’t have any waterproofing other than being raised and sitting on concrete and having a good overhang


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[sometimewoodworker]

3 hours ago, cheeryble said:

AFAIK our new house with single AAC block doesn’t have any waterproofing other than being raised and sitting on concrete and having a good overhang

Apart from render and paint I have almost never seen waterproofing used on any walls and seldom on floors either. 

 

The only consession we made for our house, that is raised a little, is to ask for waterproof cement to be used in the footings and supporting posts. I am not sure if that happened but whether it did or not we have no rising damp.

[Misab]

On 10/2/2019 at 5:09 PM, cheeryble said:

Get the sheets with the glued on 3mm foam with reflective coating.

Decent quality so the foam doesn't come off, but we felt no need for the best Bluescope..........if we have to change the sheet in 10 years or whenever it will be cheap, frame and fascias already there, the sheets up in a day.

Also didn't feel the need for hidden attachments.

If you combine the thinly (but surprisingly efficaciously) insulated sheet with above ceiling Rockwool you,ll be well insulated for heat and noise, I've now been through storms and its a pleasant muffled sound.

Go to a supplier he will calculate the prices quickly.

Thank you

[Misab]

On 10/10/2019 at 3:20 PM, cheeryble said:

 

We had The roof on mom’s original bungalow and verandah I built extendedA couple of meters or so With no insulation as it’s just at the edge.

Where we joined Mum’s Bungy to the main new house with a room 3 m wide x 5m long on the back the guys have used what I think you’re talking about, a profiled firm insulation.

We will probably slap some Chiprock GYPROC underneath it as I think that insulation will be enough as in your case.

So the job will be to attach the Jip rock to the raftersThere. Do you think the best thing is to attach timbers 2*1 First with hard as nails glue then screw the chip rock or will the Jip rock screw straight into the rafters Which after all are quite light weight?

 

 

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Thank you very much Cheeryle much appreciated.

[Misab]

On 10/4/2019 at 2:03 PM, JimShortz said:

I just had a single plane roof completed on a new build house. For an idea of costs, my roof at 26m x 9m was:

Covering: Bluescope colorbond galvanised steel, with white colour bonded on top and 25mm of bonded insulation underneath, cost just about exactly 100k Baht including delivery, flashing and and all fixings, but not including the actual installation (that was done by the people who constructed my steel roof frame as part of the price for the whole job).

 

Roof structure: all done with high quality steel box section at 2.6mm thickness, except battens at 2mm. The whole building area 26m x 7m had a 4" square ringbeam and the same beam down the centre of the building. The 3" x 1.5" rafters are them placed at 1.5m centres and 2" square battens on top at 1m centres. Rest assured that this is a super strong structure if done with good s

On 10/9/2019 at 4:12 PM, JimShortz said:

I certainly agree that single lengths is great to ensure a leak free roof, even in the fiercest storms. My lengths were 9.1m and almost unbelievably they came on a pickup with a special frame fitted (see picture earlier in the thread). I also agree that the 2 or 3mm glued on insulation with reflective foil massively cuts down heat transfer and deadens the sound of rain. I fitted it on my outdoor bathroom that I built ahead of building the main house and I am very happy with it. Mine's been on for a year and hasn't sagged or fallen apart yet, but I have seen many that have. I don't know how you go about choosing the good stuff? I guess I was just lucky. I bought that from Lion Steel in Hangdong, Chiang Mai. I'm glad to hear yours is working out well for you.

I also want to share in more detail, for anyone interested, the alternative way I chose for my main house:

For my main house I chose the "hard" bonded insulation from Bluescope and am super pleased with it. I also went for the foil bonded on its underside to prevent heat radiating downwards, but if you were leaving it exposed there is a paintable option too. The bonded insulation actually gives a flat ceiling to its underside and I have seen a friend leave this exposed on a "lean to" to his house and painted it to match the house - it actually gives a decent flat ceiling and looks good.

The real reasons I went with the 25mm bonded insulation is that it is much quieter during rain and very little heat passes through (25mm insulation makes a significant difference compared to a couple of mm). I have a gypsum ceiling fitted 8" below the roof (at the same angle) with no rockwool and have mosquito proof ventilation all the way along both the top and bottom eves.

The idea is that air enters at the bottom eve, passes between the gypsum and the well insulated roof covering, and any heat and moisture that is there leaves at the top eve. I have to say that it works really well - physics in action I guess! The idea behind no rockwool being installed is partly to save money on something not needed with this system, and also to let heat out through the gypsum at night. It seems that with the well insulated covering and good "attic space" ventilation the rockwool isn't needed - at least on my house (my gypsum ceilings are just at ambient temperature, even in the middle of the day). I also went for a white colour on top since the way my house is situated you never see the roof anyway, and it is by far the most reflective colour - again keeping the heat out of my tiny attic space!

My covering with the 25mm bonded insulation cost B100,000 including fixings for a roof of 26m x 9.1m (237 square metres). That works out at about B420 per square meter for covering (including fixings and flashings) with no loft insulation to buy. Not super cheap, but not bad either and is certainly one way to a quiet, cool, and cost effective roof. YMMV!  ????



 

steel, and no cheap C sections. Painting, welding (excellent seam welding all "linear" joints in ringbeams, rafters and battens), installation of the Bluescope covering and flashings, and installation of fake wood fascia boards, by a really good team of three welders cost me B60k Baht in labour + about the same again for steel.

Total roof cost about 220k Baht - an absolute bargain for a very strong and highly insulated  and reflective roof!  And it's not noisy or hot at all either; the bonded insulation is fantastic.

PS, I originally planned it with 1m centres for the rafters and it was the main man at Lion Steel who said for this structure (only 3.5m between each ringbeam that the rafters cross) that was excessive. He said I could go as far at 2m, using quality steel of decent thickness, but I compromised at 1.5m and am super happy with the decision.

I also think I got great welding because the guys could seam weld the decent thickness steel (I weld fairly well myself, and thin steel is a bitch, it just melts away, leaving holes). I also bought them 10kg of good rods so that they wouldn't be shy with them!

 

Thank you Jin Shortz, as I understand it total price about 1000 Bahts per square meter 

[cheeryble]

I think there’s a reputable but more economical type of Bluescope sheet called ZAKS


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[GarryP]

On 10/16/2019 at 9:55 AM, JimShortz said:

Why would you want to install a vapour barrier? To the best of my knowledge this is not normal for twin block wall homes, but rather for timber framed homes with brick/block cladding. I have an air space only, and eaves that keep the rain largely off the exterior walls anyway.

Hi Jim,

 

Are all your outside walls twin block with a cavity in between? I assume you used aerated concrete blocks. I hadn't really given it much thought, except that I would also use AAC blocks. Perhaps a single block wall would be sufficient in my case if I use the thicker blocks which are 20cm thick. 

 

As to those extractor fans you have built in, where do you locate the vents on the other side of your house?  Near the floor? I just can't picture the vents. 

 

BTW, it looks like we will go with the single plane roof too, using insulated metal roof panels similar to yours.   

[JimShortz]

On 5/26/2020 at 8:59 PM, GarryP said:

Are all your outside walls twin block with a cavity in between? I assume you used aerated concrete blocks. I hadn't really given it much thought, except that I would also use AAC blocks. Perhaps a single block wall would be sufficient in my case if I use the thicker blocks which are 20cm thick. 

Hi Garry,
We went with twin lightweight concrete blocks (but not AAC), with a cavity. I explained all of the reasons behind our choice in this thread. I think that thread covers it all - if slightly crazy!
 

 

As for the vents. Each room with an extractor actually has a bathroom on the other side of the house with a wall from it facing into that room, and the bathrooms have the windows with overlapping glass so that they are always open whilst not being possible to climb into!  All I then did was cut a hole in the internal wall of each bathroom and fitted vent covers on both sides of that wall, creating a through flow. With the extractors on there is a good wind through these vents, pulling air in through the bathroom window, straight through the bathroom wall at a high level, and on to the extractor and out (on the high side of the house). I hope that makes sense. Like these ones: 

 

I hope that's of help. Good luck with your build.  ????

 

[JimShortz]

On 5/26/2020 at 8:59 PM, GarryP said:

Perhaps a single block wall would be sufficient in my case if I use the thicker blocks which are 20cm thick.  

I missed that bit - yes for sure you would be fine with a single skin of 20cm blocks. I think the reason that not so many people go that route is that the blocks are (or at least were when I looked), substantially more expensive - a  lot more than twice the price of the 7.5cm blocks.  They would be a great choice though, and I am sure someone will be along to say that with labour they work out about the same. I guess that depends on the nature of your labour costs agreement.  ????

[bodga]

On 10/4/2019 at 2:03 PM, JimShortz said:

I just had a single plane roof completed on a new build house. For an idea of costs, my roof at 26m x 9m was:

Covering: Bluescope colorbond galvanised steel, with white colour bonded on top and 25mm of bonded insulation underneath, cost just about exactly 100k Baht including delivery, flashing and and all fixings, but not including the actual installation (that was done by the people who constructed my steel roof frame as part of the price for the whole job).

 

Roof structure: all done with high quality steel box section at 2.6mm thickness, except battens at 2mm. The whole building area 26m x 7m had a 4" square ringbeam and the same beam down the centre of the building. The 3" x 1.5" rafters are them placed at 1.5m centres and 2" square battens on top at 1m centres. Rest assured that this is a super strong structure if done with good spec steel, and no cheap C sections. Painting, welding (excellent seam welding all "linear" joints in ringbeams, rafters and battens), installation of the Bluescope covering and flashings, and installation of fake wood fascia boards, by a really good team of three welders cost me B60k Baht in labour + about the same again for steel.

Total roof cost about 220k Baht - an absolute bargain for a very strong and highly insulated  and reflective roof!  And it's not noisy or hot at all either; the bonded insulation is fantastic.

PS, I originally planned it with 1m centres for the rafters and it was the main man at Lion Steel who said for this structure (only 3.5m between each ringbeam that the rafters cross) that was excessive. He said I could go as far at 2m, using quality steel of decent thickness, but I compromised at 1.5m and am super happy with the decision.

I also think I got great welding because the guys could seam weld the decent thickness steel (I weld fairly well myself, and thin steel is a bitch, it just melts away, leaving holes). I also bought them 10kg of good rods so that they wouldn't be shy with them!

 

I'd  have used  galvanised  personally, and  did when I did  mine last  month, and also steel square  plates to join roof  steel  to columns.

Edited May 30, 2020 by bodga

[JimShortz]

2 hours ago, bodga said:

I'd  have used  galvanised  personally, and  did when I did  mine last  month, and also steel square  plates to join roof  steel  to columns.

Yes, certainly an option, but since it is all out of the rain, in a naturally draughting ventilated airspace I really don't think there will be any issue with rusting - certainly not all of the way through the thick steel that we used. Not during my lifetime anyway!  Galvanised steel is certainly very good where the metal is exposed though; but still needs painting for long term protection, or it always seems to find some spots to rust in.
I've not seen people using plates on top of losts at roof level, but sure, why not? Equally though, welding the protruding steel rebar to the ringbeam, and then filling the space underneath with concrete works fine...  Many ways to skin a cat I guess!  I have only used the plates at the base of support posts for the car port and the veranda (and in both cases lost beneath the tiles to avoid the ugly look of having them exposed).

[GarryP]

13 hours ago, JimShortz said:

Hi Garry,
We went with twin lightweight concrete blocks (but not AAC), with a cavity. I explained all of the reasons behind our choice in this thread. I think that thread covers it all - if slightly crazy!
 

 

As for the vents. Each room with an extractor actually has a bathroom on the other side of the house with a wall from it facing into that room, and the bathrooms have the windows with overlapping glass so that they are always open whilst not being possible to climb into!  All I then did was cut a hole in the internal wall of each bathroom and fitted vent covers on both sides of that wall, creating a through flow. With the extractors on there is a good wind through these vents, pulling air in through the bathroom window, straight through the bathroom wall at a high level, and on to the extractor and out (on the high side of the house). I hope that makes sense. Like these ones: 

 

I hope that's of help. Good luck with your build.  ????

 

Yes, it certainly makes sense. Thanks for the detailed description and the link to the wall thread. I shall certainly give it a good read tomorrow. 

[GarryP]

12 hours ago, bodga said:

I'd  have used  galvanised  personally, and  did when I did  mine last  month, and also steel square  plates to join roof  steel  to columns.

What do you mean by square plates. I tried googling but nothing came up. Or do you means these? 

 

 

Edited May 30, 2020 by GarryP

[sometimewoodworker]

9 hours ago, GarryP said:

What do you mean by square plates. I tried googling but nothing came up. Or do you means these? 

 

 

He probably means these 

 

available from every steel supplier in different sizes and thicknesses.

[anpants]

If there any photos of your project Misab?