Exterior woodwork project

[rick]

I have another exterior woodwork project to kick off.

Custom taper sawn tantalized wood arrived today ?. 60m of ?wood? capping to fit to a single brick think wall ? see sketch:

The wall is a mixture of concrete block & brick ?.

Q.1 should I put a DPC under the wood, this would keep it off damp wall (holds back earth beds) .. only negative I saw was that it would also trap any water that gets underneath when it rains.

Q.2 Need a good method of fixing ? just simply gluing on with no-more-nails ? is going to fail. My mate suggested using Thunder bolts ?. Issue with these if I just fitted Thunderbolts water is going to collect where they crush into wood. I could counter-bore the wood to recess bolt heads .. but to avoid these ?holes? filling with water would need to plug .. and not going to be easy to get a plug cutter in large enough diameter to suit Thunderbolts.

So anybody go a suggestion for fitting these cappings, they have to take occasionally being stood on ? but other than that they are decorative.

Using some common catalogues items as discussion points: Frame Screws

Fischer Hammerfix

or Fischer Frame fixing

Thunderbolt

RAWL LX screw

Stainless Hammer fixings ? Frame fixings ,

Q.3 at corners, I am sort of guessing no point in jointing, just mitre cut (or but joint) as any joint is going to open an close with the seasons ?

[Tim Watts]

Unless the DPC is so large that water pools, I think you'll be better off with. I assume it will unly be under the wood and not extending sideways any great distance?

Will that amount of water (1/4 thimble?) really not just disperse in short order?

If you are worried, fill it with GeoCell TheWorks which is like a silicone, but sticks much better. Mask the surrounding wood as it's a bugger to get off.

But having has a look at your drawing, I think these are overkill.

I think the top could be fixed quite satisfactorily with

6mm x 100-120mm stainless screws (from Screwfix etc). 5mm x 50mm for the battens. You can easily make or buy wood plugs for the former, recessing them by 5-10mm.

Pilot drill for stainless of that size as they do tend to shear with high torque. Or use an exterior corrosion resistant but ordinary screw.

Butt joint. As you say the wood is going to move - probably in the summer you'll get a few mm gap, in autumn, that will close up.

[newshound]

Or just decking screws into plastic plugs, self-countersunk?

[fred]

Is the nosing profiled into the wood in which case it would act as an acceptable drip rail.

and thinking laterally would it be possible to glue the dpc to the wood ?

Screw it down with a ring collar and a snap on plastic cap

or counter bore the screw hole and glue in a plug after fixing it which would be my preferred method

[Dave Liquorice]

Well done for posting a link direct to the image not to a page full of ads and requiring javascript to load the image that any browser could display natively.

I would, down behind the battens a couple of inches and folded down the wall at the back, if it'll take a fold or can be held in place otherwise trimmed off along the back edge of the capping timber.

Any water that does get trapped will get taken up by the timber and evaporated away fairly quickly. I'm assuming that the top of the wall is essentailly flat and level and doesn't have dips. Dips would need some means of draining the water away from them.

100 mm No.8 or 10 stainless every 15 to 18 inches into plastic plugs will do, I'd go for 1/3rd the width of the wall only in from the back edge of the wall. Standing on the front edge will tend to cause a pivot at the battens/wall so it's the back edge that needs holding down. The further you can get the fixing from the pivot the less force the fixing needs to provide. Counter bored and plugged if you want to hide the heads.

Also note that stainless screws do break, brass might be better, price might be an issue. IMHO there is no such thing as a weather proof corrosion free ordinary steel fixing, brass or stainless only outside here.

I'd not worry about water in holes, it'll soon dry and you say it's "tantalized" timber as well, but what is tantalizing about it?

[rick]

Would just put DPC under where wood rests on brick face. Fixing battens is easy enough, it is fixing capping I need to get right.

You mention use Stainless ... what ones do you mean - want to have direct fixing into pilot hole ... no plugs, be too fiddly to get all them to line up.

Do you mean like these - Frame Screws

Not stainless, but under wood plugs wouldn't matter that much.

If you know of better fixing .. let me know.

I used these for my decking - they were excellent .. but the capping is a lot thicker.

[rick]

Tyhe nosing will be glued & pinned to capping .. to make leading edge profile thicker (match rear edge view) and to provide a drip

My thoughts are leaning towards conter-bore .. screw fix & plug Concern was being able to plug large diam to suit Thunderbolts ... but if I used: Frame Screws

These would plug easy enough