Decking protection

[tjs83]

Hi after bit of advice.

I installed decking years ago, and never put any joist tape over joists. This decking is spaced off the ground by 2 inches.

Now I'm looking at installation of a summerhouse on the decking, and my issue is do I lift decking up where summerhouse will be and install joist tape, or lay a damp membrane on top of the decking where the summerhouse will be?

A dpm will surely protect the joists as the summerhouse will be on top?

Thanks for any advice.

 

[Why Not Indeed]

I reckon that if you lay sheets of DPM under your summerhouse, it will certainly reduce the amount of moisture getting to the deck, but any moisture that does get there is going to pool on it, so your summerhouse will be sat in a puddle. Can you stop rain getting on the DPM?

 

[big-all]

on a more practical note
what ever height your decking is will detract from your permitted allowance for the summer house as in total permitted 2500mm decking at say 250mm your now restricted to 2250 on your summer house