Ideas for Weatherproofing under the Balcony

[Flyboy]

G'day all,
We have a balcony with hardwood decking, under which we've made a BBQ/kid's play area. I was after any ideas of the best (and cheapest) way to weatherproof the decking above so the BBQ area is useable when it rains. Some of the ideas I've had so far are :

1) 6mm FC sheeting and tiling over the decking.
Cons: The thickness of the tile+FC might be a tad high, allowing water to run back through the entrance to the balcony. Also, it's merbeau decking and it'd be a shame to cover it up.
2) Some kind of linoleum or matting over the decking.
Cons: Same as above. Might fix the water problem, but would look like crap.
3) Corrugated fibreglass roofing attached to the underside of the balcony.
Cons: Over the years, dirt and leaves will fall through the decking. Might trap moisture, causing the timber joists to rot quicker.
4) A shadesail or awning over the balcony.
Cons: Prefer to keep the sun on the balcony. Also, rain may blow in under the awning.

Feel free to rip these ideas to shreds, or throw them in the bin and come up with something else:)

Cheers

[glock40sw]

G'day.
No. 3 works.
Have one end higher than the other. This will allow the water to run off to a gutter and them to a downpipe.
Try to have access to the high end. This will allow you to stick the hose in there to blow out any leaves or other stuff.

Attach 3x1/2 battens below the joists for fixing the laserlight to.

[bpj1968]

How big is the deck, in particular the length of run for the laserlight. If there is a BIG downpour there can be a lot of water sitting on the laserlight and if screwed from underneath, there's not much holding it up. Are you able to put the roofing up in pre made panels. Have the laserlight screwed onto rafters/battens and lift these up and support.

I have a 6 x 7m deck that I built a roof under when i built it. The bearers were steel beams, had rafters between and roofing on top. The joists sat about 150 - 200 mm above for circulation. I didn;t leave ecess to clean it out and after 3 years hasn't been a problem.

[Flyboy]

Thanks for the replies.
Good idea with the hose but access will be a problem. The deck is about 4m X 4.5m, and the water would have to run down the 4m length. It also gets covered in small, fine leaves from a neighbours tree so unless we stayed right on top of it I think a lot of these would fall through on to the roofing.

Had another idea ....
The gap between the decking boards is around 6mm. Anyone know if there's a caulking product, say something like the rubber strips that hold flyscreens to the frame, which I could install between the decking? Like I said, it doesn't have to be waterproof, just keep the majority of the rain off.

Cheers

[Shaun04]

No 1 wont work because the FC sheeting for tiles is 16mm thick so there goes that one.

Why dont you build a Pergola over the deck, so then it keep rain off the deck and under it.

[Bleedin Thumb]

Had another idea ....
The gap between the decking boards is around 6mm. Anyone know if there's a caulking product, say something like the rubber strips that hold flyscreens to the frame, which I could install between the decking? Like I said, it doesn't have to be waterproof, just keep the majority of the rain off.

Cheers

If you line under your boards with FRC between the joists. Then use foam joint filler strips ( comes in rolls different diameters) between your decks and caulk the joints over the filler with an appropriate mastic product you will get the waterproof effect you want but if you dont have a fall on your deck away from your house your in trouble.
Also hell of a lot of jointing!!!!:(

[Flyboy]

Shaun,
The pergola is an option, but we'd like to keep the balcony open if possible.

BT,
That sounds like its exactly what I'm after. Do you think the job could be done without the FRC sheet? Had a quick look at a couple of foam rod products (Abelrod, Expandafoam) and it sounds like they might be held in place when compressed between the decking. 36 joints X 4.5m = 162m of jointing ...... should be fairly mind numbing:rolleyes:

[Bleedin Thumb]

Hi Flyboy,
You must be keen mate, sounds like a PITA to me. Anyway yes I would still put the FRC sheets in to provide the compression for the rod, you dont want a stilleto heel undoing all your work.
Have you checked your fall on your deck?

[Flyboy]

I'm hearing what you're saying, but SWMBO has been the driving force so as far as PITAs are concerned I'll leave it up to you to read between the lines:eek:
Anyhoo, FRC it is. Just waiting for the rain to let up and I'll check the falls, but was thinking worst case is I'll also have to set up a gutter and downpipe below the balcony on one of the walls of the bbq area.
Cheers

[Barry_White]

Instead of using corrugated fibreglass sheeting underneath I would be inclined to use Lysaghts Trimdek underneath so it would give you plenty of clearance for the water to run under where it will be fixed to some battens fixed to the underside of the deck with fall on it and a gutter on the out side edge.

This would eliminate the worry of the leaves falling through because you wouldn't be able to see them.

If you had it reverse rolled in say Colorbond white you could have the white colour on the underside which would make it brighter underneath.

The Trimdek would also be cheaper than the fibreglass.

[Bleedin Thumb]

Just waiting for the rain to let up and I'll check the falls, but was thinking worst case is I'll also have to set up a gutter and downpipe below the balcony on one of the walls of the bbq area.
Cheers
No Flyboy that is a good consideration however I was more thinking of the water being able to run away from your house IE your door. You will need a minimum of 1:100 fall that is 40mm difference in height from the building line to the outside of the deck. Most decks are level so you will be real lucky to have this.
By the way is your decking timbers screwed or nailed on to the joists. If theyre screwed you may have other options.

[Flyboy]

Barry,
Good idea using white and Trimdeck looks like a better option. I'd still be a bit worried about the build up of leaves trapping moisture though.

BT,
Unfortunately the timbers are nailed. And as you predicted, the balcony looks pretty level. To stop water running back through the door I was thinking I could either
- drill some holes in the deck in front of the door and have these drain out to a gutter attached under the balcony
- place some 40mm trim in front of the door, seal with silicone, with more trim to raise the floor next to the outside trim so you aren't tripping over it. Would have to live with water ponding on the balcony, though.
Cheers

[Clinton1]

Seems like a lot of mucking around for you. Kinda hard when its the missus cracking the whip isn't it? :rolleyes:

1. If you put a roof under the deck, the fine leaves will only get to it via the gaps between the decking. If you vaccum the deck instead of sweeping the leaves won't get pushed through and you'll minimise the amount of leaf material on the roof.
2. Call me crazy, but you could break the roof into sections, build a box frame for it (with the roof on top) and hinge it. You'd need to have a disconnect for the guttering (downpipe terminates and there is a large box underneath before the downpipe continues. This would let you drop the roof for cleaning. Some threaded rod angled up from the ends to the middle would allow you to tension the frame to stop sagging. It would need a steeper pitch to counteract any sagging.
If you weld, you could make the frame from box section and use a truss design.
3. Staple fly screen under the deck to catch anything going between the gaps, again you would vaccum.

A few left of centre ideas to chew over. :D

[Flyboy]

G'day Clinton,
The hinged roof might be a bit more work than I was planning on;), but the flyscreen and vacuum cleaner .... brilliant:).
Will have a crack with the joint filler and sealer first as this seems to be the cheapest solution, but if it doesn't work out will have to resort to the under balcony roof. The joint filler might even be simple enough (and tedious enough!) for me to talk the missus into doing half the job while I supervise from the lounge:D
Cheers

[julianx]

Hi flyboy

The gaps in the decking are there for a reason, to allow for expansion and for water to drain through.
The problems with sealing the gaps is water will pond on the dec and make it slippery and dangerous, and will also promote rotting.
I'd seriously consider barrys idea, I've used this arrangment on a number of occasions and it works well. If you are worried about the leaves then pull up a few boards at the high point of the sheets and replace the nails with screws to give you access with a hose etc.

[Flyboy]

G'day Julian,
Had a play around with covering the deck with some drop sheets and it doesn't look ponding will be a problem, thankfully all the water runs over the edge of the balcony and not in the door:). Having said that, water will still sit in the gaps if I seal them. The deck has good exposure to sun and wind so I don't think it should take too long for the gaps to dry (at least on the surface), a few hours at most. Do you think rotting will be a problem under these conditions?
Cheers

[JoshuaMars]

Ive also been thinking of filling my gaps between my decking boards. Im trying to make the underneth a cubby house for the kids. Dont want the water dripping all over their stuff.

I also was think of some sort of gapping. Something like what is used to water seal windows.

Any Ideas would be great thanks.

MARSY