Layz spa & decking

[mustang86]

Hi everyone.
Looking for some advise on decking. We have just brought a house with a raised decking around the conservatory. The house is split level so the rear decked area is raised above ground level on the roof of what is used as a shed. We have a layz spa and would like to put it on this part of the decking. Do you think it will be strong enough. I've uploaded some pics of it too to help.
Thanks in advance for your help

 

[r896neo]

The joist spacings look generous and the fact that they have been notched reduces their strength significantly.

How big is it volume wise? Bare in mind 1000L capacity plus occupants will take it comfortably over a ton.

With some remedial work to the decking sub-structure it may be possible, as it stands i would even consider it. If you serious you would need an engineer to calculate the loading and advise.

If you repost this in the building forum there are some engineers on there who could give you a proper idea of loads and suitable structure.

Ask the mods to move it for you.

 

[theprinceofdarkness]

As the man said, you have to find out its capacity of water and how many occupant (4 people at 80kg = 320 KG)and add another bit for its structure, 200 KG?. The first thing is that the fixings of the wall plate are puny and so they should be boosted to 12mm diametre at 300mm centres around the load point.
As once this thing is placed on the deck, it is not likely to be moved, so I would just sister up all the joists underneath it plus an extra one each side. Glue'em with a D4 glue and as many 100mm nails toshed in as possible. The idea is to reduce the bending stress.At the ends the weight might still be taken by the old end of the original joists, which will be put under shear where they will be strong enough.
Frank

 

[mustang86]

I believe that the spa holds just under 1000 litres when filled to maximum water line..if I put it half over the existing wall underneath would that make any difference?

 

[theprinceofdarkness]

It depends where its legs are and how they takes its weight. If there are four they will neatly avoid the strong point! (unless you sit it on diagonaly)
Frank