weed membrane over joists instead of on ground

[Kevstir]

Hi guys

Me and my dads been building the framing for my decking, we kind of got carried away with our self and forgot about the weed membrane, now it would be a tad hard to put in on the ground so thinking about putting it on top of the joists, had anyone done this, cant think it would be a problem as long as its blocking light from getting to the ground.

also i got a 1.5x50 meter roll of 50gsm membrane for free, now i know its not the best but would laying 3 layers on top bring it up to a good enough standard ie 150gsm.

Here is where we are now, as you can see laying the membrane down now would be a task lol, its 3x5 meter and build on a budget of £250 so not expecting perfection, all the wood you see i got for free apart from the hand rails

Kev

 

[Kevstir]

not to worry we managed to get 3 layers on the ground and a layer of red chips, also going to put a layer on top of the joists, weeds should have no chance lol

 

[Thermo]

we always put the fabric on top of the joists when we do a deck, advantages as follows:-

whole frame is wrapped in fabric, that stops any weeds that grow laterally such as bindweed etc travelling across a memebrane on the floor and coming up through the boards

stops anything falling through such as food or something vaulable such as jewellery!

gives a much better look between the boards when finished

 

[WabbitPoo]

I have mixed feelings on this - some fabrics are very good at pooling water on them, so fixing to the joists can lead to water gathering (even for only a few hours) between the joists. I have tried both methods, and tend to prick the fabric between the deck boards to prevent this.