How to prevent a garden deck sub-base from rotting

[Paul555]

25yrs ago I made a large raised deck the width of our back garden. Not really knowing what I was doing, I probably over-engineered the thing and used a shed load of 6"x2" treated joists with hangers, spaced about 12" apart to avoid any flex. It got to the point recently where the decking boards needed replacing as the wife would no longer accept "rustic charm" as an excuse to leave them alone. I was amazed at the condition of the joists underneath. None of them showed any signs of rot at all....as good as the day they were fixed in place. Maybe ignorance worked in my favour all those years ago....or maybe I was just lucky.

 

[TheUnicorn]

Nobody’s offended, just plain bored of the endless moaning about how anything new can’t be any good because of health and safety, cheap manufacture, young people not being properly educated etc... if people are so fond of the past, stay in it.

Your point was that modern chemicals can’t be as good as old ones, for which you have offered nothing to support that. Many chemicals have been removed from use for some serious reasons, to keep people like you alive.

no, my point was that manuafacturers claims cannot always be trusted verbatim.

 

[TheTiddles]

I’ll just leave this here...

suprised to hear that, I would have said (with no actual knowledge to back it up) that with more and more health and safety and environmental legislation modern chemicals would be less effective than older stuff, creosote being a case in point

 

[TheUnicorn]

tiddles,

you seem to be putting up that quote from me as if it proves your point. it does not. I said that I was suprised, NOT that he was wrong, I clearly state that I have no actual knowledge, but that I had been under an impression that older chemicals were stronger. I didn't say that they were better, that health and safety and environmentalism was rubbish, or anything close to that, just that I had acquired an impression over the years that (for good or bad) chemicals were not as effective now, that was my impression, I might easily be wrong, but I did not state state it as fact.

I later stated that I wouldn't take any manufacturers claims as gospel, that I stand by completely.

 

[J-G]

...my point was that manufacturers claims cannot always be trusted verbatim.

That ought to depend upon which document you are reading. If it is a 'Sales/Marketing pamphlet' I would tend to agree but if it is a 'Data Sheet' then the information has to be accurate and should be relied upon.

 

[TheUnicorn]

That ought to depend upon which document you are reading. If it is a 'Sales/Marketing pamphlet' I would tend to agree but if it is a 'Data Sheet' then the information has to be accurate and should be relied upon.

that's a fair point, I was thinking more of marketing claims, and it was a fairly general statement rather than a specific product

 

[J-G]

...it was a fairly general statement...

The devil is always in the detail - and why I tend to be pedantic

 

[Stevekane]

25yrs ago I made a large raised deck the width of our back garden. Not really knowing what I was doing, I probably over-engineered the thing and used a shed load of 6"x2" treated joists with hangers, spaced about 12" apart to avoid any flex. It got to the point recently where the decking boards needed replacing as the wife would no longer accept "rustic charm" as an excuse to leave them alone. I was amazed at the condition of the joists underneath. None of them showed any signs of rot at all....as good as the day they were fixed in place. Maybe ignorance worked in my favour all those years ago....or maybe I was just lucky.

Intresting, does it say something about the quality of preserver or was it to do with the way you laid the boards? My thoughts are that for my table I will cover most of my joints with the tabletop boards, and these boards will have a drip on each side to help stop water tracking round,,,,I will report back in 15yrs and let you know how well its lasted!

 

[MikeJhn]

On this picture you can just about make out the modern equivalent of the old saddle stones.

 

[Jameshow]

Great photo, where is this building?

South East somewhere, Taylor wimpy home 2007 10 year nhbc!!

 

[eribaMotters]

I've just come back to this post and realised the following observation may help, and come as a surprise to some.
Decking timber is generally treated as UC3 and is NOT suitable for ground contact. It should only be used above ground, eg fence panels. UC4 is a more vigorous treatment and allows permanent contact with the ground, eg fence posts.
When I wanted to put a timber edged path to the bottom of a wet garden at a previous house I found a supplier who treated timber to order. I had 450mm long cut lengths of 75 x 75 along with long lengths of 200 x 38 treated to UC4

Colin