Low density decking timber.

[sandingblock]

I'm toying with the idea of replacing my deck. I have on hand some very nice totara, a New Zealand timber that has excellent durability and stability, and maybe a tad harder than WRC. I know that this timber has been used for residential decking in the past but don't know how successful this was.

It's density is about 450 - 480 kg per cubic meter (0.45 - 0.48 specific gravity?), but it's not very strong. There is no worries about defects or grain orientation - it's long and clear.

Can I use slightly thicker decking to make up for less strength and wear resistance? How does lower density timber stand up to caulking? Will the deck need reinforcing between deck beams (18" centers)?

If I go ahead this will be a laid and caulked deck, so please no plywood/epoxy advice.

[Stiletto]

I think the lack of use these days is more to do with availability than fitness for use.

I've seen old verandahs with totara t&g decking over joists at about 450 centres.
I would rate its durability as better than Kwila.

The totara I've used has been quite a bit harder than WRC.

A little experimentation may be called for. Set up a couple of 'joists' at whatever span, and measure the deflection of decking over them compared to what was originally specified. Add thickness until it is the same. Half a dozen pieces of timber max should get you there.

Dont know about the caulking.

Anyway, who is cutting down totara trees?

[Lucky Luke]

Can you get your hands onto some old kauri: top best!

Please, people: specially if you are asking for an advice, therefore excpecting people to spend time for you, could you do the effort of typing a few more letters and abandon the habit of abbreviating evrything ? (think that there are a few *foreigners* around) Whatzehell is WRC?

[sandingblock]

Western Red Cedar (WRC), sorry for the abreviation, it seems fairly common on this forum, I'm learning bad habits.

I have quite a bit of kauri, but in big sections that I want to save for another day. As for totara, it's not to hard to get hold of here in the lower North Island if you keep your ear to the ground. Trees seem to get cut on a farm now and again, resonable price too.

I think I'll follow your advice Grant and machine some up and do a trial run, maybe caulk it aswell. My instincts are telling me it will be good decking timber if treated with care, e.g. no work boots etc.

[Stiletto]

Re the caulking, remember that totara required a special primer because of its oiliness. Probably another case for experimentation.

Good luck!

[Steveh]

Lasts for tens of years (even hundreds) as fence posts stuck in the ground so guess as deck with the right coatings would last well. Not sure myself, how you would lay a single layer deck. Am presently having Ngatira restored at the NZ Maritime restoration School (sorry for the plug) but authentically laid with kauri 3/8 diagonal under and then a 5/8 fore and aft, but I know Jay has recently layed a deck on a small runabout with totara.

Remember he had some oddities with it. Probably because the oilyness.

Try contacting him at nzskippyjay@hotmail.com

[sandingblock]

Thanks I'll give him a try. I have used a bit of totara for other things and found out the hard way that oil based or poly's don't like drying on it. I found that a couple of coats of water based sealer solved this problem. I'm going to see if a penetrating epoxy has the same effect, and do some experimenting with different paying concoctions too.

[Charles Burgess]

Southern Yellow Pine (SYP ...LOL) was used extensively in the US for clipper ship decks. Very strong and durable... and cheap compared to most hardwoods.

[Bob Smalser]

http://www2.fpl.fs.fed.us/TechSheets/SoftwoodNA/pdf_files/pinustaedaeng.pdf

Be real careful buying today's American Southern Yellow Pine for boat wood. Most of what's sold commercially is Loblolly Pine, in which heartwood doesn't develop until the tree is 20 years old, and today plantation trees are harvested at 40 years and around 20-25 inches DBH.

So regardless of its resinous smell, there is very little heartwood to be found in wide-ringed plantation wood, and SYP sapwood is just as rot-prone as any other sapwood.

[Charles Burgess]

http://www2.fpl.fs.fed.us/TechSheets/SoftwoodNA/pdf_files/pinustaedaeng.pdf

Be real careful buying today's American Southern Yellow Pine for boat wood. Most of what's sold commercially is Loblolly Pine, in which heartwood doesn't develop until the tree is 20 years old, and today plantation trees are harvested at 40 years and around 20-25 inches DBH.

So regardless of its resinous smell, there is very little heartwood to be found in wide-ringed plantation wood, and SYP sapwood is just as rot-prone as any other sapwood.

Very true. SYP is the kind of wood you need to inspect personally before buying. You can test the quality of wood by driving a 2-1/2 inch 8d nail through the wide side of a 2x4...it should bend over before you can drive it home. The good wood is nearly as tough as oak to drive a nail in.