Bitumen painted OSB for garden office back walls?

[trigg91]

Hi all. I am building a 3 x 4m garden office that will be cladded with treated timber T&G on the two exposed walls. The other two walls are close to my fence and will not be visible. I was originally planning to clad those walls too but the cost really added up. Then I considered aluminium box profile but it was still a few hundred quid. The whole structure is externally sheathed with 11mm OSB and I am wondering if I could get away with covering the OSB on the invisible walls with a bitumen paint or similar waterproof paint? This seems the most economical way. Cheers.

 

[big-all]

if your planning a say 5 year life for the office may be ok may even reach 8 who knows but then how do you add extra protection to extend the life[maintenance] as required by all structure??
even treated timber requires protection every few years to last as weathering still weakens the wood

 

[trigg91]

I think this is one of the disadvantages of building so close to a fence, but was unavoidable in my case. Another idea I had was to cover in roofing felt - some others on this forum have done the same, though I don't know if it would last. There is just enough gap for me to get behind and replace the felt when needed, because the structure is built at an angle relative to the fence. Cheers.

 

[Deluks]

I used felt on mine. It will last as long as if not longer than felt on a roof.
Buy the half decent stuff and you'll get at least ten years.

 

[cdbe]

This is a fairly cheap option and will last forever.

 

[^woody^]

This is a fairly cheap option and will last forever.


View attachment 312337

That's what I did for the hidden bits, and then the normal cladding above the fence line.

 

[noseall]

That's what I did for the hidden bits, and then the normal cladding above the fence line.

I noticed you borrowed some of the shed roof tiles for you new extension.

 

[^woody^]

I noticed you borrowed some of the shed roof tiles for you new extension.
View attachment 312379

Reuse, repurpose, recycle. It's all the rage.

Next time you're back there, do me a favour and measure that frame to see if it will fit the kitchen opening I've just built - needs to be 1500 across the bottom, 1070 up the left side, 1035 up the right side and 1550 across the top.

 

[trigg91]

Thanks guys. I think since budget is tight I will go for a high quality felt that has a long lifespan.

 

[foxhole]

I just tack a heavy duty polythene sheet to rear of structures against a fence, lasts year as the sun can’t affect it.
Bar I just built is up against neighbours hedge so used 8x4 cement sheet (£20 a sheet ).To rear.

 

[phatboy]

Could glue EDPM rubber to it, should last a good 20 years without any maintenance.

 

[big-all]

iff the water falls from the roof to the hidden area, greater protection will come from using a gutter as it will both stop water splashing back up and reaching the bottom and the 2" extra overlap will also give protection

 

[robinbanks]

I've an osb boarded up window that is getting on for 8 years in the weather, no treatment. Any wood preserving spray will do; use the same stuff you put on the fence, each time you do the fence?

 

[noseall]

Steptoe would be proud of you all, lol.

 

[noseall]

That's what I did

Really...
But he's certainly used incorrect hollow soffit as vertical cladding
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Soffits are horizontal, and hollow board should not be used vertically due to the exposed nailing. So a hollow soffit board is for horizontal soffits that don't get wet.

But cowboys tend to use them because its cheaper than proper shiplap, and its quicker to do. And only idiots actually specify it on a quote.
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hollow soffit has be used (and fitted) incorrectly for vertical fascia/cladding.

It's not just poor quality, but it is actually incompetent/fraudulent, and if she gets no luck from the roofing firm, then its one for the council's consumer protection/trading standards to get involved with.

Yeeehaar!