Covering rotten decking. Featured

Depends on how many boards are rotten it might work out dearer using OSB or ply rather than simply replacing the boards. OSB even though fairly resilient to water will expand if continually wet and even expensive marine ply will need sealing which decking oils do not do.

Richard

You may need to think about water run-off. The 'grass' is presumably not impermeable and also holds some water? That would be why the boards have rotted. If you put sheet material down and it rains - then what? pooling? permanently wet all winter?

How about : Replace the rotten boards, cover with some kind of plastic grid/mesh for ventilation, replace the astroturf.

It sounds horrible.

TW

I used two pieces (200 x 100cm) of marine ply to cover a 400cm long log storage area outside. Each piece was covered in two coats of external varnish and three coats of external paint. After a few years, one piece started to show wet stains underneath and went mouldy after another couple of years. The other piece is still fine.

Are you considering removing the rotted decking planks?

Could you be in danger of trapping moisture between the old decking and the new decking boards especially in areas that have already rotted.

Depending maybe on the type of rot it may be a good idea to treat the old decking to kill any rot spores that may immediately start attacking your new "wood" covering.

Might the grass covering the boards be the cause of the rot? e.g. boards in constant contact with a source of damp?

Some of the boards had already been replaced before the grass was laid. It may have hastened the rotting.