Extension Of Existing Concrete Pool

[Bigdaz]

Hi

I will be moving to a new house in chiang Mai in the next few weeks. The house currently has a rectangular shaped concrete pool, i am looking to extend the pool down one side and possibly create an infinity edge on the new side. In addition i want to change to a salt water based filtration system from the current chlorinization one.

Does anyone here have any experience of extending a concrete pool (can it be done?) and can anyone recommend a reliable and competant contractor for this work? I would of course be interested to hear of any problems that you could forsee with this work.

Thanks in advance!

[Chaichara]

Theoretically an extension to a pool would be conceivable. The question is, can it be done correctly and economically? You would need to gather in some quotes, talk to the bidders and guage their competency. From what I see from posts in various Thailand forums, Chai Mai appears to be a bit of a problem area for capable pool construction, but of course I may be completely wrong because we generally only get to hear about things that go wrong rather than things that are successful.

When choosing to upgrade the technical systems, which will almost certainly be required if your pool is going to be larger, again, ask several suppliers for prices of the actual equipment rather than a lump sum for the extension.

I am totally in favour of salt water chlorination, but I appreciate that not all the regulars here agree with me. Again, check the prices carefully - some of the same equipment retails at double the prices between different retailers, and consider a brand for which there is genuine after sales service - everyone claims to be an 'accredited' dealer, many are not.

[fdimike]

The biggest hurle that you'll have is dealing with the "cold joint" between the old and new concrete. New concrete will not easily bond to old concrete. Additionally, you'll have some significant forces to overcome as water is not light and moving water (people in the pool) will create significant pressure against the walls. Sealing the "cold joint" will present a whole set of problems as well. I would do a heck of a lot of research before attempting anything like this and I don't mean on your own. You should consult a QUALIFIED engineer before doing anything.

[stevehaigh]

i think extending would be almost impossible to do. you would have to chip away a large amount of concrete to get to the old steel and bond in some new steel and pour more concrete but the foundation under the new bit will not have the same loading as the foundation under the old bit so i think you will get cracking at the join. i would not waste my money on it personally but i'm no expert.

the infinity edge should be doable with a lot of concrete cutting and jack hammering

[Gerald14]

I would not do it, it is next to join the concrete without creating a weak spot and sooner or later you will get problems on the joint....but this is only my opinion

[Bosse137]

Yes,it can be done! My pool,build by myself,was 9 meter.Too short it turned out,so I took down one wall and made an extension of 16 meter.Now it is 25 x 3x 1.5 meter. I have no experience,just used common sence and no problems!What I do have experience of though,is how many Thai work.That`s why I opted for doing it all myself....

As for salt or clormachins,I do not need that,just throw in some clorinpulver every other week.Over it all,I have doubble nets,one blue,one green sort. About every 3 months i need to change water and cleen the pool.Of course,this is not something you would want to use as picture on a postcard,but for my daily swimming,it`s perfect!!

[jbrain]

Yes,it can be done! My pool,build by myself,was 9 meter.Too short it turned out,so I took down one wall and made an extension of 16 meter.Now it is 25 x 3x 1.5 meter. I have no experience,just used common sence and no problems!What I do have experience of though,is how many Thai work.That`s why I opted for doing it all myself....

As for salt or clormachins,I do not need that,just throw in some clorinpulver every other week.Over it all,I have doubble nets,one blue,one green sort. About every 3 months i need to change water and cleen the pool.Of course,this is not something you would want to use as picture on a postcard,but for my daily swimming,it`s perfect!!

I have no doubts about that Some mothers do 'ave em

[Bosse137]

Yes,it can be done! My pool,build by myself,was 9 meter.Too short it turned out,so I took down one wall and made an extension of 16 meter.Now it is 25 x 3x 1.5 meter. I have no experience,just used common sence and no problems!What I do have experience of though,is how many Thai work.That`s why I opted for doing it all myself....

As for salt or clormachins,I do not need that,just throw in some clorinpulver every other week.Over it all,I have doubble nets,one blue,one green sort. About every 3 months i need to change water and cleen the pool.Of course,this is not something you would want to use as picture on a postcard,but for my daily swimming,it`s perfect!!

I have no doubts about that Some mothers do 'ave em

...and are quite `appy with `em too...

[SantiSuk]

Must be possible to have it done with no problems later.<br /><br />Surely Consulting engineers will be advising on the joining together of concrete structures of different ages and with similar and much larger pressures all the time. Needs some technical jointing elastomers I would imagine. Im sure they would do something a bit more sophisticated than butted joints. I would guess the simplest joint would be grinding the old edges at a 45 degree angle or grinding a v shape.<br /><br />I'm no builder, but I did work as a banksman on a huge sewerage works project in the Midlands (UK) after I left university and was saving money for an overland trip to India. I saw many examples of concrete jointing in high water pressure situations being built.<br /><br />Bit of research needed to find a good consulting engineer. Probably means you need a good quality builder too. Could be cheaper to demolish old with local coolies and rebuild with a standard pool builder, but you can work-up the pricing of both options.

[stevehaigh]

you should think about the ground you are sitting on too. if its level an rock hard, you may get away with it without a problem. i'm looking at a site now sitting on silt, mud and landfill and i don't feel comfortable building a new pool on that, never mind extending an old one

i agree with jbrain about the chlorine, you don't need a fancy machine, just throw some chlorine granules or tabs in one a week or so

Edited May 14, 2013 by stevehaigh

[SantiSuk]

Once a week? In my experience that might just about work in the depths of the so-called cool season, but in 8 months of the year it would give you a pool that varies by about 4 ppm over the course of your dosage cycle, which is a bit extreme. Twice a week would be ok.

[AllanB]

I am with the "don't do it" camp, a pool should be cast in one pour for complete integrity any joints will be a weak point, it may last years, or fail in months depending on your luck.

Think about your predicament when it does fail.