DIY Treated lumber

Short version: Research says borate and copper synergistically protect lumber.

Finally moved out to the sticks and able to chase that country living dream. Trouble is there's a few things I "need" (desperately want, or the boss lady insists and is therefore proper need) to have a solid foundation and these things are usually made from wood.

Well, I've got trees and a chainsaw, so for say $200 bucks I can have more lumber than I could ever use, right? (I'm still young and dumb enough to indulge this conceit).  One can dry the lumber in a solar kiln (maybe $500), acquire a planer, etc. When faced with 10K or more worth of lumber costs for these projects, it's easy to justify the acquisition of a few tools since I'm in this for the long haul. There's just one thing that kiln dried pressure treated lumber has that nobody has said you can do yourself reliably. Treat the wood

The industry says you have to pressure treat it to get good penetration. Sure, you can char it, cover it in motor oil, etc. There are sealers you can buy and paint on. Maybe you just build it all out of cedar, cypress, or redwood if you're blessed to have those sorts of trees on hand. But what if you don't and you don't want a black porch. There's very little consensus that Google will readily offer on treating lumber yourself effectively.

Some people say you can cut lumber in midwinter when the moon is waning so there's less sugar in the wood for pests to feast on. A satisfying natural solution but still feast they will. So what is to be done for the stubbon DIY'er who doesn't want a partner in a few years to say "I told you so":


Wood Preservative Systems Containing Copper and Borates: Efficacy and Synergy
https://static1.squarespace.com/static/5b354bd6f8370a13b49308c4/t/5bb3937c71c10b1f16f34496/1538495370404/Wood+Preservative+Systems+Containing+Copper+and+Borates+Efficacy+and+Synergy.pdf

A first glance indicates that borates help the copper absorb. Copper slows borates from leaching. Maybe special compounds form in the wood when you combine them.

So my present intent is to treat some boards with boracare, then maybe copper azole (water based) or an oil based copper. Then weather seal it all.

Or find a bunch of cedar trees. That would be way easier. If you guys have a better solution I'm all ears. Or is it eyes? Whichever...

Dusty, I suggest you get modern materials for such an important part of the building.
Use either concrete or steel posts.
Timber and even treated timber can fail in particular cases, buy using say, concrete stumps you can be up and
going within hours, not days or weeks with the system you have spoken about.

John C Daley wrote:Dusty, I suggest you get modern materials for such an important part of the building.
Use either concrete or steel posts.
Timber and even treated timber can fail in particular cases, buy using say, concrete stumps you can be up and
going within hours, not days or weeks with the system you have spoken about.

I'm looking long term to build a large back porch, perhaps a pergola eventually, and a shed. Modern methods in my region generally use treated lumber with metal hangers. To buy the materials outright while avoiding additional debt I'm looking at well over year, maybe longer, and downsizing. Bad debt is bad, good debt is better, less debt overall is best I figure.

Fair point, but if you compare treating you own wood, with purchasing concrete or treated timber stumps
you may find the purchase a good use of debt and time.
By using your own timber on top of the stumps you could have the deck set out in a week perhpas.
What do you think?

Had I the resources and time in your situation this is what I would do. You may have a different take, but since you're asking for ideas...

I would try to find some field stone large enough to support the deck (or pergola) as a foundation. I would spend a lot of time choosing the best rocks and then try to pull a Mr. Chickadee:

As far as the wood itself goes, I would try to find the best naturally rot/bug resistant wood available to me. Maybe that is cedar. Maybe it is cypress. Maybe it's just cherry (wow a cherry deck).

I would probably char it, or maybe just the underside. I don't know what happens when you char things other than cedar though.

If at all possible I would build a roof so that rain and sun exposure is limited.

Lastly I would expect to do yearly maintenance on the deck/pergola.

For the last reason especially I wouldn't build a large deck. I'd keep it as small as possible while still allowing me to do what I want on it.

Do you live some place you can get black locust lumber?  Borate spray it for termite protection and a tiny bit of fire protection and its natural rot resistance should do the rest.

Here is a previous topic on permies about the toxicity or not of treated timber.
https://permies.com/t/72359/pressure-treated-lumber-bad-find
Now I do not know the truth of all the comments, but I do know scraps should not be burnt, so I take it something is amiss.
Given that I use alternatives where I can, concrete, steel etc.
But I watch people everywhere burnt it, even when they are told it should not be!!!
I hear, ' its only me doing it", what does it matter?, who cares? etc.

C. Letellier wrote:Do you live some place you can get black locust lumber?  Borate spray it for termite protection and a tiny bit of fire protection and its natural rot resistance should do the rest.

I mostly have sweetgums, oaks, a hickory, birch, pines and cedars on the few acres around my home. I also have 100 acres of pine that's almost ready to be clear cut at my disposal as well.

I looked at Black locust at your suggestion, and it is an interesting wood. I'll keep my eyes open for some on the property, and I'll probably plant a few. Maybe I can make something from them when I retire.

L. Johnson wrote:Had I the resources and time in your situation this is what I would do. You may have a different take, but since you're asking for ideas...

I would try to find some field stone large enough to support the deck (or pergola) as a foundation. I would spend a lot of time choosing the best rocks and then try to pull a Mr. Chickadee:

As far as the wood itself goes, I would try to find the best naturally rot/bug resistant wood available to me. Maybe that is cedar. Maybe it is cypress. Maybe it's just cherry (wow a cherry deck).

I would probably char it, or maybe just the underside. I don't know what happens when you char things other than cedar though.

If at all possible I would build a roof so that rain and sun exposure is limited.

Lastly I would expect to do yearly maintenance on the deck/pergola.

For the last reason especially I wouldn't build a large deck. I'd keep it as small as possible while still allowing me to do what I want on it.

I think there may be wild cherry on the property. A cherry deck would be lovely. :)  

I'm going to have to roll this one over some. I'm trying to find a reasonable middle ground between land art and construction. Since it's more an art building going fully natural and using traditional joinery on a pergola makes sense.  I've looked some into traditional joinery and such and this is all pretty interesting to me.

I'm not sure where I'd source good stones though. I have access to sandstone, but I don't think it's compares to stones like granite for construction purposes.

John C Daley wrote:Fair point, but if you compare treating you own wood, with purchasing concrete or treated timber stumps
you may find the purchase a good use of debt and time.
By using your own timber on top of the stumps you could have the deck set out in a week perhpas.
What do you think?

I do appreciate what you're saying, and I've rolled around what you're saying quite a bit. My present assessment is that I can build smaller and quicker at roughly the same expense. Or I can build more over a longer period, while accumulating tools instead of materials. My plans at present are to build a small deck coming into the home using bought materials. I really need it before the rainy season comes along for safety reasons (and domestic tranquility). Plus I should probably be familiar with modern building methods before trying to fly off into advanced woodworking and all.

Regarding deck construction. I've rolled over using traditional joinery and all of that, but, as you mentioned, failure of a structure could be catastrophic. I will definitely use metal brackets and fasteners on the structure and the metal brackets that raise supporting beams mounted in concrete. The last thing I need is a big accident during a family BBQ.

Since I have a good chainsaw and trees already, the cost saved on just a few 6''x6''x12' posts basically compensates the chainsaw milling equipment and a few gallons of boracare and copper. The cost saved from joists and decking for the back deck could be put towards a planer.

Of course I'm not really factoring my time into all of the calculations, but the satisfaction of doing it myself carries some weight. I do want to be cautious of being overly ambitious and stubborn tho, so I'm trying to make sure that my approach is sensible, even if more labor and time intensive.

but the satisfaction of doing it myself carries some weight

I understand this comment. I have done and still occasionally go that path even when good sense would be to get outside help / expertise.
I built a house / cabin entirly with hand tools, now I discourage people from doing it if they are time poor.

The OP said he has cedar growing on his property.

Would using cedar rather than treating wood be better?

Anne Miller wrote:The OP said he has cedar growing on his property.

Would using cedar rather than treating wood be better?

I'd definitely prefer to build it all out of cedar. Love that scent! I've found 3 fairly large cedars so far that I'll likely harvest, but that will only get me so far. I'll probably leave the largest and oldest out of respect for something much older than me. I figure I can make a lovely garden shed/workshop out of them.

Mostly I was bothered by the notion that I needed uncommon wood, or a pressure tank to create wooden structures that could withstand the critters and the elements, and I wanted to share what I'd found in a research paper. Which incase I didn't say clearly elsewhere: borax soaked lumber coated in copper naphthene has excellent rot resistance, and is something that an average DIY'er can reasonably achieve affordably.  The borax leaches out over time, but the oil based copper coat keeps it inside the wood. Interestingly, the borax seems to transport the copper deeper. Borax and copper are minimally impactful on the environment as far as treatments go. Of course tung oil and charring are more natural alternatives.  

Timbor also seems to be a good product for similar applications it just doesn't penetrate as deeply. Maybe that doesn't matter much since the threats to the lumber do come from the outside.  

I have not heard of Timbor, but I found this out;
- Is timbor toxic?
Timbor is made from the element Borate, which is a natural occuring element in the earth.
It is very safe and non-toxic.
Timbor will last for years on the shelf as long as it is not exposed to moisture or water.
- How long does Timbor treatment last?
The manufacturer states that Timbor will last for the life of the wood as long as the wood is not exposed to rain or flooding.
It will stay in the wood forever because of how it bonds to the cells of the wood.