To coat wood frame or not?

[hardycreek1]

Hello, we are in the midst of building a 12x30 greenhouse attached to our house. We have the foundation set and the wood frame up, next comes the bracing and the twinwall. Question: should we treat the exposed timbers? I've thought about shellac, varnish, linseed oil, or just leaving it unfinished? Our climate is low humidity with lots of wind.

I'm thinking if I apply a few costs of something on the wood, it will need to be re-done every year or so, which would be a lot of work. And in my retirement years I'm trying to avoid work, not create it

 

[Chuck]

A lot depends on what type of wood you are using. Is it a treated wood? If you are using untreated pine it is almost a must to have the wood sealed with an exterior wood sealant, otherwise it will split, crack and warp. There is a lot of difference between a wood sealer and varnish, shellac or linseed oil. Linseed is a much better sealant than varnish or shellac but it will turn an ugly black color when exposed to the weather. I have had excellent results with Seal Once Nano+Poly. It is a water based polyurethane

 

[hardycreek1]

The wood is untreated cedar and fir.

 

[Chuck]

The wood is untreated cedar and fir.

The cedar will last for years if properly nailed although it will turn dark with age. The fir will last a long time also, If you get good kiln dried lumber. If it were me I would still seal the lumber with a good sealant such as I mentioned earlier.

 

[hardycreek1]

Thanks, after doing a good bit of research it seems the best option is to seal the wood. It's looking like tung oil will be the best choice.

 

[Chuck]

Thanks, after doing a good bit of research it seems the best option is to seal the wood. It's looking like tung oil will be the best choice.

Tung oil is good stuff but it is almost as bad as linseed oil in turning a blackish color. But if you put a fresh coat on every year it will give you good service. All you have to do is wash, let dry and re-apply.

 

[hardycreek1]

How often are you applying Seal Once Nano+Poly?

 

[Chuck]

How often are you applying Seal Once Nano+Poly?

After initial 3 coats on vertical surfaces about 5 years and on horizontal surfaces about 3 years but, this is a Texas climate where things don't last as long as most places. Then just power wash and re-apply