Thread: Decking on crushed rock

In theory sounds fine. I'd you are confident that whit wants won't be an issue then drainage sounds fine.

As it would essentially be a floating platform you may want to give consideration to it 'drifting'.

There may be a tendency for it to want to lift in places. A star picket and tek screw in place may prevent this.


Dave

The Turning Cowboy

Good point about the drifting. One edge will be an existing garden bed edge made with real railway sleepers, so the bearers will be tied to this, that should nail down one edge. Star pickets to stop it lifting, I knew there was a reason that I have been keeping the bits of starpickets that are useless for fencing, these will do for the other ends of the bearers.

Good advice!

Glad to assist. WIP is your next obligation


Dave

The Turning Cowboy

Originally Posted by bloodandsawdust

Greetings,

I need to lay a deck over some scrappy ground but the deck needs to be only 100mm from the surface, so no room for the usual joists & bearers. What I am thinking is to rip some old redgum sleepers and fenceposts to 100mm x 100mm and then bed them in compacted crushed rock, and nail my decking on to that. The rock will support the bearers and also give good drainage. Does this sound like it will work? After all it works for railways!

I have a lot of scrap redgum that I pickup from hard rubbish days. It's sitting in a huge pile in the yard waiting to be sawn up, and I would much rather use it for something than burn it for firewood.

Personably if that's what you are going to do I would place damp proof membrane between the timber bearers and the decking

Originally Posted by Trevor2417

Personably if that's what you are going to do I would place damp proof membrane between the timber bearers and the decking

Always do. I pick up half rolls of this from all the rubbish that gets thrown away when a new house is built, so I always have some handy.

I had a similar issue when doing my deck at home and chose to dig down and level the area so i could put stumps in and have air flow under the bearers.

Short term you will probably be fine but after a few years of walking on it you might compress areas unevenly which will lead to bouncy areas and places where water might pool.

Just a thought.

Ben

I would get a posthole digger and put some piers down to ground surface level and tie the deck to those. Also it will make it a lot easier to get true levels from the top of the piers. If you choose to do what you have mooted the whole underdeck area will have to be levelled or it will quickly become a nightmare.

Keep in mind the dreaded white ants if you're putting red gum straight onto the ground. The railway sleepers were soaked in creosote which kills most things (including people who worked with it). If you're red gum is untreated it would be like a buffet for termites.

Trav