Thread: Poured concrete walls

One of the companies I have been in touch with in my quest for a builder does poured concrete walls - they make a form, including spaces for windows and doors, then pour the complete walls in on go.

The price seems competitive so far (still waiting for details) and its certainly quick (apparently 79 days from start to finish) and I imagine strength wouldn't be a problem, as the walls are reinforced with re-bar and there are no "posts" as such, but my main worry is insulation.

They claim they are "nearly" the same as the small red bricks, which isn't really anything to boast about, but its hard to find any specifics on the web, apart from basement walls which give 'R' values for 8" thick walls. As these poured walls would, I believe, only be 4" thick that seems to indicate that at the bottom of the insulation heap are small red bricks and poured concrete (0.4), then cinder blocks (1.0, varies), then 7 - 10 cm q blocks way ahead (3.25 - 4.2).

Any views?

Any advantage to poured concrete, apart from speed?

Is poured concrete really such a bad insulator - the posts in the house I'm renting seem a lot cooler to touch in the heat of the day than the cinder block walls, which are baking?

FWIW I should probably add that its a single storey house, so strength isn't an issue even with the planned CPAC (Monier) roof tiles.

There is nothing stopping you from adding an insulated stud wall inside the concrete.
Also allows for more flexible wiring and plumbing...

Originally Posted by JohnG

my main worry is insulation.

Originally Posted by Necron99

There is nothing stopping you from adding an insulated stud wall inside the concrete.

Indeed, you could add stud and plasterboard with rockwool sandwiched between.

Always remember the sun - where it rises and falls - and build accordingly.

Poured concrete is extremely strong, much stronger than other wall types. It's commonly used for basements in other countries. However, concrete has the very worst r-value of any building material, worse than red bricks. When you gradually heat up all that heavy mass of concrete in the daytime, all that heat has got to go somewhere. It will try to get inside. I don't think it would be advisable to make up your own strategy to deal with it unless you understand concepts like thermal bridging. Why not make a cooler house with AAC blocks and go from there rather than starting with an oven and trying to insulate all that heat out? And if you really like poured concrete, why not consider something more modern and appropriate like insulating concrete forms (ICF)?

What is it poured onto mate ?

Do you still use a traditional footing ? or is it poured from 1 metre below surface in one huge slab ?

Why not arrange a visit to one of the houses built this way...late afternoon. Ask the homeowners?

Incidentally, a house not too far from us was built with preformed concrete walls...saw a big stack of 'em like sheets of gyproc..looked to be about 4-6" thick covered with what looked like chicken wire.

There isw a factory going up near me, they did it by pouring the floor first, getting it very smooth with a helicopter, rotary trowle, unlike Thais withy their terrible finnish. They then on the flat floor, bocked up the walls to size, they did 3 of for different sizes, the boxing was about 15" high so multiple layers could be done, one after the other, then coated the flat concrete with release agent, sprayed on. Fitted the reo, up on stands so to keep it some where near a 1/3 up into the wall. Then poured the concrete to the desired depth, in this case about 6", smoothed that off again with a helicopter, when that set, sprayed another coat of release agent and did the next layer of wall, simple. Hope this makes some sence.

I think the OP is talking about pre-cast concrete walls...commonly referred to as tilt up construction in the states.

I have been watching three apartment structures going up here in Chiang Rai using this method of construction. Fast, clean and utilitarian...however there are major columns poured and load beams in every floor and inter connections.

If you're building in Thailand are you concerned about heat or heat loss/cold? both?

My house is all red brick with concrete floors and wall finished. No problems with heat either way. Good attic circulation is perhaps more important. Red brick is strong as needed for a house build and have seen skyscrapers use this material in Lima Peru with success. Most not load centered anyway. Floor beams and roof beams carry the loads distributed out to the columns.

Oh, in that case note q-con has great big wall panels as well. They go up real quickly and slot into each other but you need heavy machinery to put them in place. Maybe ask your builder for a quote using the light weight q-con wall panels instead of ones made of normal concrete. But make sure he is the type of person who will follow all the instructions precisely so the job isn't botched. AAC is different than concrete and its precise needs should be understood and followed.

Originally Posted by nigelandjan

What is it poured onto mate ?

Do you still use a traditional footing ? or is it poured from 1 metre below surface in one huge slab ?

As far as I can see its "traditional" construction for the foundation and roof - footings, pilings, etc, as needed, and a metal roof frame - but its the walls that are different. Instead of posts with re-bar, with bricks/blocks between the posts, all the walls get poured on-site in one go with re-bar re-inforcement in the walls and no posts.

Originally Posted by ltnt

I think the OP is talking about pre-cast concrete walls...commonly referred to as tilt up construction in the states.

I have been watching three apartment structures going up here in Chiang Rai using this method of construction. Fast, clean and utilitarian...however there are major columns poured and load beams in every floor and inter connections.

If you're building in Thailand are you concerned about heat or heat loss/cold? both?

My house is all red brick with concrete floors and wall finished. No problems with heat either way. Good attic circulation is perhaps more important. Red brick is strong as needed for a house build and have seen skyscrapers use this material in Lima Peru with success. Most not load centered anyway. Floor beams and roof beams carry the loads distributed out to the columns.

No, that sounds like what I think used to be called "pre-fab". This is actually pouring the walls on-site into a form, all in one go.

We're in Loei (Thailand's coldest province, supposedly) so its both hot and cold that we need to prepare for.

I think you're 100% right about the attic circulation - I'm hoping that the CPAC Monier Cool Roof system, with vented eaves and vents built into the ridge tiles, will solve that one and still look good and keep out the wind and rain. You've prompted me to ask about that too!

Originally Posted by canopy

Poured concrete is extremely strong, much stronger than other wall types. It's commonly used for basements in other countries. However, concrete has the very worst r-value of any building material, worse than red bricks. When you gradually heat up all that heavy mass of concrete in the daytime, all that heat has got to go somewhere. It will try to get inside. I don't think it would be advisable to make up your own strategy to deal with it unless you understand concepts like thermal bridging. Why not make a cooler house with AAC blocks and go from there rather than starting with an oven and trying to insulate all that heat out? And if you really like poured concrete, why not consider something more modern and appropriate like insulating concrete forms (ICF)?

I think you're spot on - we really don't need all that strength in a single storey house, but we could definitely do without living in a heat sink in the summer and a fridge in the winter!
I'm also not keen on building a brand new house then trying to find ways to insulate it if I can avoid the problems from the start.
AAC blocks seem the way to go - I've got enough problems trying to find a decent builder already, without letting them experiment on me with ICF! The bigger AAC panels are a possibility, but I think that may be a step too far for any builder I end up with, who is likely to have enough problems doing the basic AAC blocks properly.

I think you've made my mind up .....

Originally Posted by crepitas

Why not arrange a visit to one of the houses built this way...late afternoon. Ask the homeowners?

The problem is that the builders are quite a way away, in a different province, and there's nothing like that local - it was just that I was trying to cast my net wider for potential builders and these came up as "willing to travel".

It sounds good for a row of 3 or 4 floor town houses, but I'm less sure about a one storey - it may well be strong walls, but foundations, roof and everything else is just left up to whatever local "team" they can get and I've had enough experience of that already to last several lifetimes!

You might want to take a look at my little house build John , using Nano concrete blocks ,, goes up very quickly and is nice and cool

I have not read the whole story, however, in my idea the style pf poured concrete walls give sense only when the walls are also carrying the construction. In Thailand all houses are made with columns (Sau), then no meaning to pour concrete in-between the Saus.

Beside the problem with the heat absorpsion that will radiate long into the night. The blocks and/or bricks are here quite cheap, also the workmanship.

Better to make the double walls by blocks or bricks, so the walls can be also carrying when combined with rebars embeded inside and the concrete poured around (to create a column where it is needed).

Then only you have to persuade the builder not to make the bloody columns (delaying the construction by many weeks), they will be confused.

Originally Posted by nigelandjan

You might want to take a look at my little house build John , using Nano concrete blocks ,, goes up very quickly and is nice and cool

Can you give a link, please?

Originally Posted by Klondyke

I have not read the whole story, however, in my idea the style pf poured concrete walls give sense only when the walls are also carrying the construction. In Thailand all houses are made with columns (Sau), then no meaning to pour concrete in-between the Saus.

Beside the problem with the heat absorpsion that will radiate long into the night. The blocks and/or bricks are here quite cheap, also the workmanship.

Better to make the double walls by blocks or bricks, so the walls can be also carrying when combined with rebars embeded inside and the concrete poured around (to create a column where it is needed).

Then only you have to persuade the builder not to make the bloody columns (delaying the construction by many weeks), they will be confused.

I agree - I've realised that doing anything even a little out of the ordinary is far from a good idea for any number of reasons, so its going to be just plain block walls.

Originally Posted by JohnG

I agree - I've realised that doing anything even a little out of the ordinary is far from a good idea for any number of reasons, so its going to be just plain block walls.

In another thread I just saw a link where the traditional way of buliding is shown very clearly. https://teakdoor.com/construction-in-...ml#post2204965

What I see always once passing by, such construction skeleton to make (together with foundation excavation) takes few months (unless the builder is a superman), spending lot of material and workmanship as well. Still do not see any wall.

If you do it with a double walls with blocks or bricks (no Saus), simple foundation ring in a trench 30x30, you can see the house within 3 weeks. Moreover, you will get a cool house for half the money.