Garden room flooring joists exposed to elements

[MQ88]

Hi All,

I had screwed in flooring joists for my garden room 2 years ago and covered them in tarp which later on broke in some areas. I wonder if I can use these joists or should I buy new ones? I was told by the seller that this timber was treated, any advice will be greatly appreciated. Posting some pictures below

 

[freddiemercurystwin]

What are you asking exactly? All that timber look OK to me. Better if there was a layer of dpm between the blockwork and joists.

 

[chirpychippy]

This is mine as it is at the moment, the subsoil has a damp proof membrane covering it held with many slabs. All timber that is in contact with concrete blocks has been dunked in bitumen and wrapped in a dpc, but in such a way that rain water can drain. All timber that is in contact with the ground has been wrapped in dpm, but so as not to suffocate the timber "dry rot" It's all suspended off of alot ot of concrete.

Yours looks fine, tanalised timber will rot if it's exposed to persistent moisture such as where your joists are sitting on concrete blocks.