Dip treated vs pressure treated vs neither

[Steve-O]

Hi and seasons greetings! :ho2

Further to my recent post garden-buildings-direct-t85293.html I have have found 3 local shed companies who's sheds look pretty good quality and are reasonably priced but each supply sheds that are treated differently, one is pressure treated, one dip treated and the other companies are not treated at all...

So my questions is, which is best for a general garden shed? Bearing in mind any I buy will be treated with a good quality shed stain or paint.

They are tried to 'sell' their reasons for treatment or lack of it but I want some impartial advice.

Thanks in advance.

Stephen

 

[Myfordman]

Pressure treated would tend to be better than dip or none but it still depends on how long the items are processed for.

Dipping for 24hrs say (unrealistic) will possibly better be better than pressure treating for a couple of minutes.
Then there is the type of chemicals used and how the process has been neutered by legislation.

Might be worth seeing if there is a BS spec on pressure treatment - possible quoted in building regs for structural timber and insist on that as a minimum.

In terms of ready made items, treatment after manufacture will be needed to ensure cut surfaces are treated too.

 

[John15]

Pressure treated will be the most durable, (10 years + ?) before you need to treat the timber again although recent legislation has reduced the strength of the chemicals used previously. Dipping I would say is marginally better than treating it yourself with a preservative. I've always treated my sheds myself every 3 or 4 years and they seem to last indefinitely.

John

 

[Chrispy]

Pure guess work here so probably wrong but my thoughts are that pressure treated is best but unless the shed manufacturer has the equipment will have been done before manufacture so not so good, were as dipped will probably be done after manufacture so all the cut ends and holes etc will get done so may be better?

 

[tomf]

The main thing is to keep it off the ground and keep it dry/ventilated.
Green pressurised 'water' (tanalith e) is still seen as the best or the brown stuff (tanatone). It is no where near as good as it used to be as they removed the arsenic from it.
Class 3 timber which is probably what the shed is made from is still not suitable for contact with the ground so make sure you isolate and raise the base from the wet ground.

But it really depends who you talk to, if you can get proper creosote or make your own, although it not very nice stuff, this is probably the best.

A non treated piece of pine will last an awful long time outside if it is kept dry most of the time and allowed to dry out after it gets wet.

 

[Steve-O]

Hi guys, thank you ever so much for the replies and advice, it is much appreciated.

It's going to be going onto the garden patio but I was planning on putting down additional bearers perpendicular to the floor joists, such as garden fence posts or flag stones or even bricks just so that the shed timber avoids contact with the ground, do you think this will be suitable or a good idea? The shed companies seem to just have the sheds/joists just sitting directly onto the ground when on display, surely the shed isn't going to last very long just like that??

Thanks again

Stephen

 

[Jacob]

....

A non treated piece of pine will last an awful long time outside if it is kept dry most of the time and allowed to dry out after it gets wet.

And western red cedar (the trad chicken shed material) will last even longer.
If you get the design and construction details right you won't need any treatment at all.
If you are going for paint I'd highly recommend linseed oil paint (Holkham Hall or other makers) as it is incredibly durable compared to modern paints and surprisingly cheap (in use - not by the tin!)