Northern Box Flooring

[Sledge Forward]

Northern Box Flooring applied to an external domestic deck, finished as a boat deck.[Ie sika flex joints].
Whos got the fair dinkum fixing method, the quailty of this non Aust. timber, and any other suggestions.

[journeyman Mick]

Get a hold of the sikaflex product manual, if you are laying a strip deck the sales reps should be falling over thamselves to give you a manual as you'll be buying plenty of product. Just a tip, I don't use the Sika primer for painting inside the seams, I use a two pack timber preserver from Wattyl. Try www.sika.com.au or call them on 07 3266 4733. I've laid a bit of decking when working for others but a few years ago I priced a job myself so I took the precaution of ringing Sika to get the manual as I had to guarantee the job myself.

Mick

[Sledge Forward]

What timber did u use on your deck. Teak & Beech[45x12] are most commonly used as u know. I want to match the flooring layed indoors [Northern Box 80x19].
recon I'll cut the groove off the flooring board leave the tongue to form the seal/expansion gap. And epoxy glue down.Will the board cup?

[journeyman Mick]

Don't want to rain on your parade but....
All the decks I laid in this manner were boat decks, either Teak, Vitex or White Beech. As far as I know these are the only species suitable and the order I listed them in is the order of suitability. If I was asked to lay a strip deck on concrete which it looks like you want to do judging from your other posts I would refuse. In a situation as you have described, i.e. laying on a concrete slab, epoxy is out. Core drilling holes in the slab for ventilation won't do anything unless you somehow tunnel under the slab to all the holes. All the timbers listed above are naturally oily so they repel water, however the no. 1 enemy of a laid timber deck is FRESH WATER. Laid timber decks last on boats because the salt water acts as a preservative, stopping fungal growth. Laid timber decks are traditionally washed down with sea water. Timber boats often have bags of pool salt thrown in their bilges if the hull doesn't leak but the deck does, thereby letting rain water in. Are you laying joists on the slab and then laying your deck on top? In this case you will have to plug every screw hole which is also very time consuming. If you really must lay a deck in this manner I would be placing a waterproof membrane on the concrete first, then laying the deck in a bed of the Sika bedding compound. You would still need to screw the boards down as well. You would need to counterbore each fixing, then plug each hole, glueing the plugs in with epoxy. You would then need to trim the plugs, prime the seams with two pack timber preserver, caulk the seams and then after three days sand the whole deck with a BELT sander. Not a drum sander that the hire places have for sanding floors but a professional's belt sander. I've never seen these for hire (they cost $3000+) so you'd have to get someone in to sand the deck, someone who has sanded boat decks before. Also you need to caulk the seams within a narrow ambient temperature range otherwise air bubbles form in the caulk, causing leaks. All the work needs to happen in the shade to stop the caulk or the bedding forming bubbles. I would strongly reccomend against trying to lay a caulked deck as it is very specialised work. I did a fair bit of it whilst working for others before I was game to do a job on my own bat. A caulked deck will probably cost you 5x a standard deck in materials and take about 10x as long. If you really want to try it make yourself a table with a caulked deck top and see how much it costs you in time and materials.

Mick