Can anyone recommend a cheap spreadable glue.....

[aires69uk]

I want to bond some plastic sheeting to a piece of plywood that will act as the underneath of a shed base. I will be flipping the shed base upside down and attaching some marine plywood to the joists. But I want the plastic sheeting to be on the outside of the plywood. So it'll be like a sandwich:
1/ first plastic sheeting
2/ second plywood
3/ insulation inbetween
4/ lastly the shed base
But Long story short - can anyone recommend a cheap spreadable glue that I can trowel onto the plywood and then fix the plastic sheeting too?

 

[HERTS P&D]

The shed will rot quicker, buy a new shed and treat it will the correct product. You can still treat the timber underneath due to it sitting on timber bearers, do this every 2 years and the shed will last a very long time.

You can even put dpc on top of the timber bearers, so that no damp can go up into the base of the shed.

I done this to a shed over 20 years ago and it's still going strong.

Andy

 

[aires69uk]

I don't understand - why would the shed rot quicker? Surely the plastic sheeting is going to act as a damp barrier?

 

[big-all]

wood needs airflow to remove moisture
any moisture that gets behind the plastic is trapped and nothing kills timber quicker than constant level off damp [around 22%] wood can be soaked and dried it will not rot until the moisture level stabilizes at the correct level
thats why fence posts rot at ground level but are ok above and below

 

[aires69uk]

Well I am lining the inbetween of the joists with some Knauf Rock Mineral Wool slabs so I cannot leave them exposed to the elements. I have had the plywood indoors in the house for a week drying out. Surely if I employ some sort of heat in the shed in the form of a Thermotube heater for example, the plywood shouldn't be getting any moisture from either outside or inside?

 

[big-all]

its not exposed to the elements underneath just splashes and damp air neither will bother wood polythene will
the point is it needs the roof the walls to be 100% watertight and no internal spillages to stop water perculating onto the polythene