Waterproof Concrete.

Meningate · 12-12-2019 1:32pm #1

Hi, I'm planning on building a water feature in the garden which will require a water storage sump of around 2000 litres. Plastic tanks of suitable size run into thousands so I'd like to cast a re enforced Concrete tank just below ground. It would be great to mix something with the Concrete so that the finished tank would be watertight, but I'm equally happy to do a normal mix casting and then render it internally with two coats of waterproof rendering. The question is, what waterproofing method to use and where can I get it? Advice appreciated.

Calahonda52 · 12-12-2019 3:28pm

My concern would be poor compaction and cracking, not to mind the work

2m by 1m by 1m internal

How will you cover it to make it safe?
Best think of tanking it

Meningate · 12-12-2019 3:35pm

Thanks Calahonda52. I plan to hire a vibrating Concrete compactor during construction and it will be re enforced with 6mm re bar mesh, as will the Concrete lid. Happy to tank it, but what with ?

tabby aspreme · 12-12-2019 8:42pm

Could you tank it with a pond liner, or if you have access for a truck or digger put in a concrete base, and put a large concrete pipe on it.

bunderoon · 12-12-2019 8:51pm

https://www.paintingaluminium.com.au/aluminium-painting/what-is-2-pack-paint/

Atlantic Dawn · 12-12-2019 8:55pm

Put a couple of layers of fibreglass directly on to the concrete.

Alucan · 12-12-2019 9:13pm

Casting a concrete tank would be the most expensive option by far and very labour intensive. Also safety becomes a concern as the hole needs to be much bigger and the sides sloping back to avoid the danger of it collapsing when you are in the hole putting together the form work. A plastic tank suitable for under ground use should be available for around € 1400 delivered to your site the benefit of plastic would be that it is light to lift into the hole.
The next option would be precast concrete delivered to site with a crane truck and lifted into the hole should be doable for around €1600.

Still waters · 12-12-2019 9:19pm

Could you build a block on flat enclosure and drop 2 1000 liter ibc tanks into it, they're on done deal for 70 or 80 euros

KK4SAM · 12-12-2019 9:20pm

Why not couple two IBC's together and fill around them with lean mix ? water proof for life.

Car99 · 12-12-2019 9:21pm

You can buy a 4000L precast septic tank for €800 why bother building it yourself.

BryanF · 12-12-2019 10:44pm

KK4SAM wrote: »

Why not couple two IBC's together and fill around them with lean mix ? water proof for life.

Wouldnt even need to encase. Just keep them out of the light..

listermint · 12-12-2019 10:50pm

Pond liner pond liner pond liner

dathi · 13-12-2019 1:08pm

if you google "concrete koi pond sealer" you will get names of sealers for concrete ponds i have used a ibc container underground to collect rain water , sat it on concrete base and used a week mix of concrete between it and clay walls and topped it off with some concrete lintels if you are doing it this way make sure you fill the ibc with water before you pour the concrete walls to stop the ibc from distorting inwards .if you need to connect the two ibc together you will find lots of fittings on line catering to the koi pond community

Meningate · 13-12-2019 1:52pm

Thanks you everyone, a very wide range of ideas there to look into, many of them new ones to me. I'm sure my problem will soon be solved !

KK4SAM · 13-12-2019 7:15pm

BryanF wrote: »

Wouldnt even need to encase. Just keep them out of the light..

He wants it below ground,depend on what vehicular traffic is in the vicinity.

Waterproof Concrete.

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