Timber Raised Pond Design

[Tony Pond]

I'm building a raised timber pond for the garden and would appreciate some advice on the load bearing capability of the timber structure. The pond is 1.2m x 1.8m and 1.1m high, using 32mm thick T&G timber and a PVC liner. The corners are notched and fairly tight. It will hold 1650 litres of water.

I'm trying to work out the pressure on the structure walls and the load bearing capacity of the wood, and prove that the current design is up to it. Also, I wouldn't mind scaling up the design and would like to know how big I can go.

I've made a few calculations and have a good idea of the force on the walls due to hydrostatic pressure, but I cant figure out how to calculate the bending capability of the timber, it is C16 Grade T&G.

Cheers in advance

 

[Gemma]

Hi and welcome to GPF Tony
I'm sure someone here will be able to help you out soon

 

[MitchM]

You didn't mention which wood species or the board width, and span tables don't deal with short lengths that you are working with.
I would be more concerned with twists and knots in the wood pieces.
You can have a look through this document to get an idea of the information you're looking for.
http://www.awc.org/pdf/codes-standards/publications/wcd/AWC-WCD2-ToungeGroove-ViewOnly-0402.pdf

 

[Tony Pond]

Hi, The board is 140mm, EU Grade C16. I've looked at span tables but they're more concerned with loadbearing joists taking the weight along the grain.

I have calculated the stress on the walls as 1.5psi and would really like to know how that will hold up with the timber I have.

 

[MitchM]

I don't think you're going to find more specific information regarding bending stress numbers unless you contact the wood manufacturer.
Personally, I think you'll be fine.

 

[Jhn]

Agree with Mitch, think you will be fine. Depending on how much bigger you go it may need support to prevent bowing.