Hypothetical wood question
Hypothetical wood question
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Lord Pikey

Original Poster:

3,257 posts

244 months

Wednesday 6th May 2009
quotequote all
Hypothetically. If you were making a tempory roof rack out of wood to bolt to existing roof rails that would allow 3 adult males to get a nice few of "mad friday" what would be your wood of choice?

Chip Board

MDF

Plywood?

Thanks

LP

mbl4

111 posts

219 months

Wednesday 6th May 2009
quotequote all
none of the above, they are crap when wet. the best thing i could think of would be decking planks. designed to take the weight and withstand the weather without an issue. also easy to cut and play about with.

Lord Pikey

Original Poster:

3,257 posts

244 months

Wednesday 6th May 2009
quotequote all
mbl4 said:
none of the above, they are crap when wet. the best thing i could think of would be decking planks. designed to take the weight and withstand the weather without an issue. also easy to cut and play about with.
That ads to the complication and expense. My plan was to clamp the wood to the roof rails using exhaust u brackets. So fitting is a simple case of drilling a few holes and tightening a few nuts...

I was going to bolt a few grab handles down....

what if i painted it with a sand and paint mix...........?


Dave^

7,893 posts

282 months

Wednesday 6th May 2009
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not wood i know.... but.....

how about ali chequerplate with angle iron/unistrut bracing?

just a thought......

Nick M

3,632 posts

252 months

Wednesday 6th May 2009
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Plywood, but not thin stuff. I think that should be the stuff (from your list) most able to take the weight without bits breaking off. But don't scrimp on something like 10mm stuff wink

Nick M

3,632 posts

252 months

Wednesday 6th May 2009
quotequote all
Lord Pikey said:
what if i painted it with a sand and paint mix...........?
I'd be more inclined to use epoxy resin with sand in it - that should help stiffen the plywood as well.

mrsxllifts

2,501 posts

228 months

Wednesday 6th May 2009
quotequote all
Not that I am in anyway technical but what about decent thickness of marine ply? With enough support should take thw weight and be able to withstand La Sarthe style weather.

-Lummox-

2,007 posts

242 months

Wednesday 6th May 2009
quotequote all
mrsxllifts said:
Not that I am in anyway technical but what about decent thickness of marine ply? With enough support should take thw weight and be able to withstand La Sarthe style weather.
Seconded. Marine ply requires no mucking about with paint etc, so is a lot easier, even if it costs a few quid more. Stronger too.

ETA: three adult males? You're brave. You do realise the weight capacity of the roof rails on most estate cars is around 75kg max, right? Hope it's 3 exceedingly waifish males, and the handles are so you don't get blown off the roof whilst stationary...

Edited by -Lummox- on Wednesday 6th May 13:57

m0ssy

920 posts

221 months

Wednesday 6th May 2009
quotequote all
If its just for the weekend I would recomend T&G chipboard 8' X 2' lengths. Around £4.99 a sheet, durable, workable, easily transportable and held together by glue and paintable.

I don't personally think you would even need to get moisture resistant, no point as it only needs to last a weekend after all.

Lord Pikey

Original Poster:

3,257 posts

244 months

Wednesday 6th May 2009
quotequote all
You make a good point mr Lummox.

Im hoping that rating is set at a SWL for roof box at 80 mph with a few large twisting and bending momments.

Hence my engineering logic dictates that 3 * 80KG blokes will be fine at 5mph dukcing water bombs

Edited by Lord Pikey on Wednesday 6th May 14:38

ginettag27

7,088 posts

298 months

Wednesday 6th May 2009
quotequote all
Not MDF and not Chipboard either! MDF would be too heavy and goes to mush if allowed to get wet, chipboard is similar.

Ply, should be okay, if thick enough

plus possibly Flakeboard.. (or maybe not, due to the Chipboard issues above)

or some Pine boards.. the sort that garden gates are made from..

It depends if you need a whole "slab" to put stuff on, or just a few cross members to balance stuff on..

-Lummox-

2,007 posts

242 months

Wednesday 6th May 2009
quotequote all
Lord Pikey said:
You make a good point mr Lummox.

Im hoping that rating is set at a SWL for roof box at 80 mph with a few large twisting and bending momments.

Hence my engineering logic dictates that 3 * 80KG blokes will be fine at 5mph dukcing water bombs

Edited by Lord Pikey on Wednesday 6th May 14:38
You can but try... how about this:

http://www.wickes.co.uk/Sheet-Exterior-Plywood/Ext...

2 sheets of that should be plenty.

Cobra Andy

472 posts

257 months

Wednesday 6th May 2009
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you could always try Sterling Board - exterior grade, its available from any timber merchant not the DIY boys, it will stand up to any weather thrown at it over a weekend and is pretty sturdy. Comes in various thicknesses, but I'm guessing 18mm will be just right for your needs.

FredericRobinson

5,006 posts

261 months

Wednesday 6th May 2009
quotequote all
We boarded the roofrack of our Series 2 Landy out with chipboard a couple of years back, coped with the weight of 4 chaps & a wicker conservatory furniture set fine for the full week