Greenhouse help.

[Fat ferret]

Hi all, I'm preparing for a lean to greenhouse against a rough stone wall. Greenhouse installers want goalpost type frame against the wall made of 2"x4" to attach the greenhouse to which has to be plumb and level. Lead flashing will cover it but wondering what the best timber would be. I want something that wont rot anytime soon as the greenhouse itself should last a lifetime. I know I can get meranti or iroko locally.

 

[John15]

Oak is very resistant to decay.

John

 

[Fat ferret]

Ok American white oak is the only kiln dried oak I know I can get. Use that then?

 

[blackrodd]

Put a polythene bag or two around the bottom of the uprights, before concreting in and I would say any decent hardwood would last.
Dig the pit, lay the 2 base/padstone's at the same levels each and concrete in place.
HTH Rodders

 

[John15]

Ok American white oak is the only kiln dried oak I know I can get. Use that then?

Both White Oak and European Oak are very durable but European Oak would be more readily available and cheaper.

John

 

[Doug B]

Accoya, wouldn't bother with anything else out doors.

 

[RobinBHM]

American white oak is generally not advised for external use in the uk.

Meranti is moderately durable.

Iroko is very durable and would be my choice. European oak is very durable but would be more expensive and is prone to surface checking.

Accoya is the most durable timber but very expensive and will require stainless fixings. It also should not touch lead.

 

[Doug B]

To be fair you wouldn't need the lead so it would be cheaper to use Accoya as apposed to hardwood & lead.

 

[Billy Flitch]

Not just on price but also on durability Larch is a excellent out door timber ,just not fancy enough for some people.
Even driven into the ground it will last,built quite a few boats out of it.
If you do decide to go with it best pick it out yourself two things to look out for are pockets of pitch and cup shakes that can lead to delamination but as said if you pick it out yourself there should be no problem.

 

[Fat ferret]

The greenhouse has a single brick strip foundation but the wood is to make up for the unevenness of wall so obviously need to measure from wood for foundations.

Lead goes in a mortar joint above wood and over the wood and over the greenhouse frame. Need lead flashing whatever.

I like larch for fencing, gates, boardwalks ect but greenhouse could last 50 years hopefully whereas larch might not. Will try an get iroko or accoya. Don't think I can get European oak locally but will ask.

I also need to scarf it to make a 6m length.

 

[porker]

Any reason why you wouldn't consider Red Cedar? I have a lean to greenhouse made of this which must be 40-50 years old and the wood is still in good condition. I'm no wood expert so this is more of a question than a recommendation. Just interested to know.

 

[dickm]

+1 for Western Red Cedar, IF you can get good quality; seemed surprisingly difficult to get it up here. Larch also, which may be easier to get though, again, quality can be variable, so pick it carefully.

 

[Fat ferret]

Would use western red cedar if I could find any, out on a limb here for timber.

I only need around 12 meters.