Sri Lankan house build

[Bewdy]

In May I will be building a house in Sri Lanka, we are doing voluntary work out here and we have found a family who desperately needs a home, so we want to build them one. I’m an experienced developer in the UK, having both built from scratch, as well as renovated plenty of properties. I’m very hands on.

Things are done rather differently in Sri Lanka, no building codes/regs, or planning issues that I am aware of. We are planning to build a very modest, small home for them and I am thinking basic reinforced ground slab, single skin 100mm blockwork construction, timber frame cut roof with metal covering.

In Sri Lanka (and lots of other Asian countries) a lot of residential properties appear to be built with shuttered reinforced concrete piers, usually on all corners of the property and also and what seems to be at 2-3m spans, and filled in with single skin blockwork. It’s not a practice carried out in the UK much. I don’t understand the need for these concrete piers, and why they don’t just return the concrete blockwork around.

I can understand the potential added vertical strengthening given by the piers, but if anything the fact all the infilled concrete walls are butted up to the concrete piers seems to then defeat this purpose?

What I’m wondering is if I’m using 100mm blockwork, whether I need these reinforced concrete piers. I’ve attached a plan of the proposed and also an indicative image of the typical local construction method.

Seeing as though they don’t seem to have prestressed concrete lintels out here, I am thinking of adding a reinforced concrete ring beam all around the property level with the top of doors and windows.

I’m interested to read peoples comments.

 

[jasonzyx]

In a 4 meter long single skin wall, there would be a pier or two in the UK. A pier of double skin blockwork.
On the 6 meter long run you might have 2 or 3 piers.
The blocks may not be concrete blocks but terracotta blocks, although judging by your picture they may be concrete blocks.. A single skin wall has little lateral strength. The concrete piers provide that strength, plus they are reinforced with steel bars, and the connecting lintels provide a sturdy frame.
Your internal walls might provide that lateral strength.

If you have never worked in the tropics, be prepared for a real shock! It's not just the sun, it's the heat also! You'd be better off paying locals to do the work, plus you'll be adding money into the economy. But I doubt if they'll understand your plans, just provide a sketch.
The metal roof will be extremely noisy when it rains and make the house very hot when it's not raining. It may be the cheapest option but it's not the best, unless you can provide a ventilated double skin.

The concrete ring beam is usually added at the top of the walls.
Follow the local traditions in building. It's been done that way for a reason.
By all means supervise and ensure they are not skimping on materials, etc.
Are you rendering the outside and painting? It'll need it for weatherproofing.

Have you thought about what to do with the rain coming off the roof, you'll need to.

 

[Bewdy]

Thanks for the reply. We’ve already been out here for 3 months doing renovation work for a charity, painting outside and repointing paving stones so yes it’s hot! But we are getting used to it. The sound of the metal is a good point, I was planning to line it in timber, but they also widely use asbestos corogated roofing out here too, I’m not dead keen on using that, or clay tiles also (which would be very laborious). We have a very tight timescale to compete the job as we will be removing a family from their albeit dlitapited mud house while this replacement goes up.

Most of the blockwork seems to be concrete here, so I wondered if the lateral strength from the connecting internal wall about half distance and the retuning walls to the front and rear would be enough without these piers. They are not huge runs, or heights after all.

The outside will be rendered eventually.

 

[^woody^]

It's not in an earthquake zone, and a quick google indicates that blockwork and brick is common, and it seems that concrete frames are only used where the design requires - covered verandahs and balconies and floors roofs built as part of the frame.

I did read that it is common for the poorer people to build their houses in stages over many years, adding rooms and storeys as money comes available. So that may dictate why a frame is chosen.

You can cast concrete lintels like we did 50 years or so ago. No need for a ring beam.

 

[ivixor]

That's also the standard construction across most of eastern europe. Probably requires less skill than blockwork. Just knock up some bits of ply and pour concrete.

 

[Notch7]

Interesting project.

Are you going to do a thread wth progress pics?

Live threads are far more interesting than a load of pics posted at the end