JimShortz

Yes, with thin "village spec" rafters you may be able to self-tap. I have no experience of this. I was determined to build mine to out last me Yes, the green boards don't cost much more, why not... My galvanised strips are at 40cm centres, but 60cm can work fine too - or so my guys told me. Again, for the extra few Baht why not go for 40cm and play it safe.

Actually, looking at where your connecting room appears to be, you may well be able to use water resistant gypsum boards instead of concrete boards. This is what is fitted on my outside roof extension and in my indoor bathrooms. This is much more resistant to humidity than regular gypsum, and you are still able to finish it nicely (concrete board, unfortunately, you can always still see the joins). You will need to drill through the galvanised strips into the rafters, unless your rafters are made of toffee, lol. With my 2.6mm thick steel rafters they had to be drilled for sure, then self tapping screws into those holes.

Yes, exactly that - nice and simple. You can buy those strips from Global House, or any of the other big building suppliers.

If your planning a house, also note the 3 high level "exhaust holes". They have Mitsubishi extractor fans on the inside and are plugged into smart plugs so that in the early hours of the morning, when the outside air is coolest, they pull in air via vents in the opposite side of the house (the low side) and blow out the hot air from the highest point of my ceilings . It is AMAZING how much cooler they make the house; for almost free - the best thing I fitted! My roof is single plane, so those forced fan vents make a heap of sense. Having ventilation in the cement board of both the bottom and top eves also creates a natural air current between my roof and the gypsum boards - gotta love natural cooling (supplemented by AC when needed, of course!). Single plane roofs may not be beautiful, but they sure are practical!

...actually, probably clearer on this one:

I don't have a better pic to hand, but you can just about see it at the far left of the picture. On the hidden side it has what is effectively strong mossie screen "tape" stuck over the rows of holes (it appears to be epoxyed in place). Not many places in Chiag Mai have it, but I know Global House now stocks it. I wanted it to keep the geckos out of my roof space!

Yes, I agree, not wood! The guys who installed my gypsum board (inside), and concrete board with mosquito proof ventilation holes (outside, under the eaves) installed a layer of light metal galvanised strips that are then screwed into directly through the board with no need for drilling. Mine are at 40cm centres to prevent sagging (at their recommendation), but 60cm centres is basically fine too - or so they told me. Like this (and it is cheap as chips):

That certainly looks like a very interesting offer, with a SEER rating of 18 and a very cheap price! LG apparently make pretty decent ACs too?

Thank you. Does he sell AC, or just an installer? ...and thank you to everyone else for very useful input. I'm still unsure which way to go, being unconvinced that the higher SEER will in reality make sense vs the cheaper one - but I guess not a vast difference either way. Still thinking...

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!

I am beginning to think the lower priced unit may indeed make more sense, especially if I can get reasonable priced installation. I don't suppose you are in Chiang Mai and can direct me to better value installation? Anyone got recommendations for good quality good price installation in Chiang Mai? Thank you

I have three small bedrooms (around 12 square metres each) to buy ACs for. I have pretty much decided to buy Daikin for their excellent reputation, unless someone wants to convince me otherwise? My two Daikin Inverter options being considered are: FTKQ09SV2S for B10,560 with a SEER value of 16.66 FTKC09RV2S for B15,990 with a SEER value of 20 Clearly the second one is cheaper to run with the higher SEER value, but by how much? I am partly confused because the second one has a "magic eye" function that allows the room temperature to raise a little if it senses nobody in the room. I'm guessing that this feeds into the higher SEER value, BUT since these are bedrooms and will contain people if the AC is on then this is essentially irrelevant. I guess what I am asking is does anybody understand how SEER values are calculated, and is it likely that for me the real world SEER values may be actually much closer together. Does anyone have any thoughts on these ACs? Or alternative AC suggestions (high SEER and good value!) I am pretty much sold on the more expensive of the two. I am in Chiang Mai and was thinking about ordering from these guys, at B18,900 including installation, piping, brackets, etc. Is that a good deal? Anywhere else in Chiang Mai I should be asking? (I want a local company so that I have somewhere to go if there are problems).

I should've mentioned that the Bluescope steel roofing came from the place found at (18.761777, 99.041102). It doesn't seem to come up in any English search, but this is the main Bluescope place in Chiang Mai and the prices via them are comparable to non-Bluescope elsewhere. You will, of course, need a Thai speaker. We found their service and prices to be excellent, and with a large product range too. If you buy Bluescope from anywhere else it is much more expensive. I don't know for sure, but I assume all of the other outlets are just resellers from this place - with associated price mark-up. You're welcome...