Screw fixing

[rick]

Thought I'd be the odd one out and post a d-i-y question.

Need to fix a load of 38mm treated batten to exterior brick and block walls. There is not much imposed load ... these are battens onto which will be fixed wood cladding.

Wall has earth on one side so brickwork is wet .... will fit a dpc between batten and wall to help.

Battens will vary depending on wall height, between 400 & 600mm high

Looking for a good fixing screw that will last ..... had thought of 2 of these per batten ...

However on a bit of Googling saw some comments such as

That says you should not use these for batten fixing only plug & screw method.

As batten is 38mm thinking of using 100mm screws as per link ... would give a good 60mm fixing.

Anybody any comments as to best approach and what screws ...

[newshound]

Don't know how well these will tolerate wet in the long term although with multiple fittings per batten I would have thought they would be pretty secure.

If you've never used them, Multi Monti bolts are pretty good. They need an accurate pilot hole, but one thing they are good for is that you can go quite close to the edge of a brick in safety. They are normally easy to remove and replace (handy in one of my applications where I once needed to take a trellis fixing down once to allow materials to be passed over a boundary wall). They seem to have effective plating.

[GB]

It actually says: "These fixings are no good for battens as the screw part sticks through the top of what you are fixing. You need a flush fixing for battens, so good quality countersunk screws and wall plugs will work best."

However, the DeWalt ones you linked to are countersunk, so that particular point is not an issue.

[rick]

OK I read that different .. thought poster had issue with the fact that the screw would have treads in the batten ... and that was the issue. Could result it not pulling wood tight against brickwork maybe ?

The Monti variant in other reply has unthreaded portion (bolt rather than screw) .. and that should negate that issue.

[rick]

Multi Monti bolts are pretty good. They need

These ones ? .... is that right?

[tabbypurr]

stainless or brass then.

NT

[T i m]

I would normally go for a std plug and SS screw myself, that way the screw won't rust away (and no coating to damage) or expand and crack a brick etc.

Being as the load will be in shear they don't need to be any thicker than you can get in a suitable (long) length?

Cheap enough to go for more / batten?

Cheers, T i m

[GB]

I would drill a clearance hole in the timber and then drill the concrete through that.

Otherwise, are you planning to drill the timber with the masonry bit and then go through into the concrete? That might work, I guess, but it's not something I've tried.

[David Lang]

All you need is a Bosch multi material drill bit & some hammer fixings.

[newshound]

That's it. I've only used the hex headed version, don't recall seeing those when I was shopping (some time ago)

[harry]

Stainless steel woodscrews. Available from Screwfix. Plastic plugs.

[rick]

Was thinking of getting type which are part threaded .. usually if no portion of the thread in the fixing it pulls to wall better ...

Not necessarily these - but this type:

but maybe it isn't necessary, and fully threaded screws will be OK

Now this assumes I use Red rawlplugs these are 35mm long - and 90mm screws.. not as long a fixing as I'd like, but if good holes & good screws maybe it will be OK. No high loads after all.

[rick]

If I used concrete screws - would pre-drill timber first.

[rick]

=

Hammer fixings would work out expensive as I need around 400

[T i m]

True, but only if 1) You haven't first drilled a hole though the batten that doesn't allow the screw thread to grip the batten [1] or

2) the batten is sufficiently soft and the wall fixing good enough to pull the thread though the batten.

I think either would be ok, noting the above etc.

I'm sure it will, depending how sound the wall is etc. There is nothing stopping you inserting a plug a little deeper, (or use those long strip plugs you cut to length yourself?) as long as the batten is snugged up to the wall.

Quite. Friction between the batten and the wall should stop any side loads on the screws (if you have set the plugs in a bit deeper) and the screws will be in shear anyway (so you could probably just 'hang' the battens on screws that long with no plugs at all ).

If you are at all unsure, just put an extra screw or two in?

Cheers, T i m

[1] I have no issue using all threaded screws though battens like that but I won't use full threaded screws (machine or wood) when the thing being retained needs to rotate at all (unless it's in a bushing etc).

[David Lang]

£35?

[Muddymike]

I used countersunk frame fixers for similar job. Just drill right through batten into wall, countersink, hammer in frame fixed.

Mike

[GB]

Then the threaded shank wouldn't be an issue. Just make the clearance hole big enough.

[GB]

I've never used one of those, and I'm interested in how they work in practice. Can you drill the wood part with the drill's hammer action on? Can you get them with SDS fittings?

[Andy Burns]

I used them to drill through uPVC into brick/block for for frame fixings, I'd say hammer off through wood, hammer on when you reach brick, even if starting in brick I'd have hammer off and slow gear just to avoid wandering at the start.

Not seen them.