looking to start construction of water tank 2.5 x 2.5 x 2.5 deep to help get through next dry season. Construction in 4 " concrete block inground but after purchasing concrete blocks through a large dealer, have grave doubts about the strength of these, with 2 skins on a 5 inch hand poured concrete base with compacted sand around it. Hand dug the hole about to start the base, then realised these blocks may not be enough to support the walls I was wandering if there are others out there who have found better alternative way of construction. Do you know where 8" blocks can be bought close to Ubon Ratchathani

Any advice much appreciated.

Dane

kazoo55

If you wanted to strengthen the block wall add some steel between the the 2 courses.

Use some vertical steel rebar and add some horizontal ones and tie these to the vertical ones.

Will cost extra for the steel and a bit more concrete will be required between the blocks around the steel but would make a solid strong wall.

Remember the pressure on the wall from the outside will only matter if the tank is empty, when it is full the outside  pressure will be matched by the inside pressure.

On 8/11/2020 at 9:12 AM, OOTAI said:

kazoo55

If you wanted to strengthen the block wall add some steel between the the 2 courses.

Use some vertical steel rebar and add some horizontal ones and tie these to the vertical ones.

Will cost extra for the steel and a bit more concrete will be required between the blocks around the steel but would make a solid strong wall.

Remember the pressure on the wall from the outside will only matter if the tank is empty, when it is full the outside  pressure will be matched by the inside pressure.

 

thanks Ootai, considered your suggestion as well to strengthen block wall using these inferior 4" blocks. Intended laying 2 skins staggering horizontal & vertical joints backed by 3 to 1 sand cement dry mix between skins & excavation. First slab 4" laid down with first skin of 4" block work with water stop  installed. 7 days cure then lay another slab inside 4" block work. 7 days later final skin of blocks hope it works.

Intend to cement slurry both skins then let it cure. 7 days then lay up render on inner skin hopefully it will work.

Tried every where to get solid 8" blocks but nothing. I have built large tanks & swimming pools using 8" block with great success in Australia & NZ but product quality lacks here sadly. Building shop assured me that these 4" blocks will do the job,I believed him. After having the blocks delivered I realised these blocks were just rubbish, but the building company blamed manufacturers so it goes on. I was not going to get any money returned so i have suck it in & make it work.

Thanks Ootai

Q-con blocks laid on their side would do the trick.  That would be about 15,000L of water.  Using 500L a day for 2 people, showers cooking, washing machine and watering a few plants that's only good for a month.