How to seal a 4' x 4' wood box that holds water?

[plowhog]

I would caution you that there is a huge difference between the longevity of today's redwood, and the redwood of 100 years ago. Today's redwood will rot out in as soon as ten years. I am told it has to do with the relatively younger age of redwoods being logged today.

That is an interesting perspective. Hmmmm. A friend advised bypassing "typical" redwood and focusing only on heart redwood. Like you, he advised any sapwood in "typical" redwood would rot out fairly quickly. But I didn't consider age of heart redwood could have an impact.

I could get bags of concrete to the site using pack animals, or my logging winch, a pulley up high, and a long cable.

My skills with concrete are low. Would a monolithic pour for a concrete box be best, or is it reasonable to pour the floor first, then add the sides later?

As you said, a wood top on a concrete box would work well. There is a 2nd distribution box in this irrigation system exactly like that .... but it is in an easy to access location.

 

[jyoutz]

That is an interesting perspective. Hmmmm. A friend advised bypassing "typical" redwood and focusing only on heart redwood. Like you, he advised any sapwood in "typical" redwood would rot out fairly quickly. But I didn't consider age of heart redwood could have an impact.

I could get bags of concrete to the site using pack animals, or my logging winch, a pulley up high, and a long cable.

My skills with concrete are low. Would a monolithic pour for a concrete box be best, or is it reasonable to pour the floor first, then add the sides later?

As you said, a wood top on a concrete box would work well. There is a 2nd distribution box in this irrigation system exactly like that .... but it is in an easy to access location.

The redwood heartwood is what is rot resistant, not the white sapwood. The age of the tree only matters in that the older trees have more heartwood. Boards cut from younger trees have a high percentage of white sapwood, which is not rot resistant.

 

[ultrarunner]

My uncle built cisterns with concrete in one pour and always added extra cement to the mix for water tightness plus reinforced with steel.

 

[plowhog]

Boards cut from younger trees have a high percentage of white sapwood,

I found a source for true heart redwood in 2x12. It was difficult to find.

Price is $8/ft, but they could charge double that because I can't find it anywhere else ......

 

[plowhog]

reinforced with steel.

Agreed. I add rebar to any concrete project I do.

 

[ponytug]

A friend runs one of the local redwood logging / mill operations. The way he explained to me was that in the older trees the heartwood was so rich in resin/phenolic compounds that the wood was almost black. His statement was that the old, extra dark wood lasted longer. Made sense to me, for the same reason that sapwood rots so quickly. My only frame of reference is that the surviving old, old redwood spacers on the barbed wire fences here are black rather than red. (No idea if the redwood sticks were black going up, of course. Some of the barbed wire is of outdated design, but I have no idea if it was new when it was installed.) YMMV!

All I know is that neither recent redwood nor recent pressure treated lasts very long in my soil in ground contact use, even when I get burial grade pressure treated.

Have you thought about a hybrid design? Use a tote, but upcycle the frame with concrete to keep the bears out. You could put in all of the bulkhead fittings in before putting it in the woods, and it would save you some form building.

If it were me, I would do the concrete in one pour stopping is only going to generate a crack to cause issues later.

All the best,

Peter

 

[plowhog]

neither recent redwood nor recent pressure treated lasts very long in my soil in ground

When I built my wife's raised planters I learned that the formula/chemical for pressure treated lumber change some number of years ago. Maybe that's why it performs poorly compared to the past.

Still kicking around ideas-- thank for the thoughts. This is one of those projects where there are several ways to approach it, but each approach has some sort of unwanted drawback.

 

[ruffdog]

Maybe a concrete D-box?

Distribution Boxes - Jefferson Concrete Corp.

 

[pmsmechanic]

Around here the Hutterites make concrete walls. 2" cement with rebar, 2" insulation and then another 2" of cement and rebar. I'm thinking you could do something similar with a single 2" precast wall of concrete. You could use a piece of plastic pipe cast into the concrete for the appropriately sized bulkheads. Precast the walls and the floor so that you can bolt them together once they are in place. Up here we use a product called Ramneck for sealing joints. It's a tar and fiber based product that when used in between joints seals and waterproofs the joint. I'm sure there are similar based products that California irrigation districts use to maintain their systems. Alternately you can use the plastic product mentioned previously to seal the joints.

Now to get all this up the hill. 500' of cable and a well anchored pulley and you can drag the walls and floor up there with one of your tracotrs. Either skid them on the ground or use a small wagon. The toughest part would be to get the floor in place. Alternately you could use cable to pull your concrete up the hill and mix and pour the floor in place. What ever you decide is easier. Two husky men should be able to handle a 2" x 2' x 4' piece of concrete wall to place them.

 

[ponytug]

When I built my wife's raised planters I learned that the formula/chemical for pressure treated lumber change some number of years ago. Maybe that's why it performs poorly compared to the past.

Still kicking around ideas-- thank for the thoughts. This is one of those projects where there are several ways to approach it, but each approach has some sort of unwanted drawback.

Yes, the rules changed to favor copper (MCA, CCA, ACQ, ACQ with ammonia) in the preservative awhile back. Some parts of the country may still have access to arsenic and chromium versions (e.g. Wolmanized), but not in California as far as I know.

The bit that I missed at first is that there is ground contact grade, and burial grade, which has twice the amount of preservatives in it, with the added ammonia version to disfavor insects. I used ground contact pressure treated from Home Depot, and didn't catch that the intended use as fence posts didn't qualify until after they were installed.

Personally, I wouldn't use any pressure treated wood in a water contact use out of a concern of chemical leaching.

While we are kicking ideas around, there is also the possibility of using ICF to build the tank, which gets you the concrete forms and then plaster the inside with a high cement plaster and then a waterproofing layer, like Redguard.

All the best,

Peter

All the best,

Peter