cistern question

pretty common, depending on the crack it may be trivial to fix.

Having built a new home on St Croix & living in it for 8 yrs, I can assure you that your cistern will leak. Ours began to have slow leaks within the 18 months after construction.

My opinion on leaks— There are too many small earthquakes (most are never felt) that cause the re-bar reinforced cement filled cinder block walls to constantly shift & tiny cracks (hairline cracks) develop.

We solved our slow leaks with the installation of a custom made flexible cistern liner (like a big bladder) instead of constantly re-sealing the walls.

The bladder option sounds sensible. Is the material suitable for water used for drinking (using UV & filtering)? Would you mind sharing the approximate cost? This is a great forum!

I have also read that folks use fiberglass liners after repairing their cisterns.

I've never had a problem like that with mine, however mine was, and i believe most today, are of poured cement construction. Meaning the walls of the cistern were formed out with wood during construction, rebar was then added inside, then cement was poured into the forms. No cinder blocks were used in the building of the cistern.

The cost of material & labor to install a cistern liner depends on the size (L-W-H) of the cistern. Yes the liner is approved by NSF for potable water. There is a company on St Croix (Kevin Moran-owner) that will measure your cistern, order the liner, materials, & install. He uses the same company that we used for our cistern liner.

Here is Kevin Moran’s website:
http://www.clearwaterstx.com/

Here is Mfg’s web site:
http://dlmplastics.com/product/rainwater-harvesting/cistern-liners/

singlefin

Poured concrete cistern walls are a lot more expensive to do than doing cinder block walls. So my guess is the vast majority of cistern walls on STX are of cinder block construction.

I believe new construction codes require a poured cistern. I haven't seen any new construction with cinder block cisterns myself.

They still build them with block, but the fill the voids with a Zypex additive mixed in with the concrete. The Zypex pentetrates the porous block. Its supposed the work well. Much cheaper than solid poured walls.
My cistern is solid poured walls with cove at the bottom. It was poured in 1965 and had no sealant inside just bare concrete and didn't leak. I'm sure it hadnt even been cleaned for 25 years unil I cleaned and sealed it. I lucked out on that one.

We have thick vinyl liners in our cisterns.

They never leak!

We have thick vinyl liners in our cisterns.

They never leak!

EXACTLY MY POINT. Thanks vicanuck.

We have thick vinyl liners in our cisterns.

They never leak!

EXACTLY MY POINT. Thanks vicanuck.

They should last forever too because the sun is the only thing that could limit their age I would think. I don't know of anyone installing them on STT. Seems like the way to go.

who installs vinyl on STX?

MSC

Same as told you several days ago. Cistern liners are vinyl

http://www.clearwaterstx.com/

Ah, yes. Thanks!

You can also call Lenn DePalma at AquaTek. Lenn is a very professional installer and can provide the 60 mil vinyl pool liners. He is in the process of building his retail location at Five Corners next to Car Zone. His number is 340-713-2782 or 340-642-0519. He installed my UV and triple filter water purification system and I was very impressed.