How to make pressure treated wood look old quickly

Question

We are adding a porch onto our old tobacco barn and are using pressure treated lumber.

We started in July to prepare for my daughter's outdoor wedding in late October. I would like for the porch wood to look old like the barn.

I have seen a lot about making new wood look old by using a vinegar and rusty nail or steel wool solution, but no one ever discusses whether or not you can do this on fairly new treated lumber. It has been hot and dry since we began this project... can someone advise me on this?

Answer 1

Using a light gray and/or brown stain would be the only option I can think of that would work in that timeframe on PT lumber. If you apply it by dabbing/daubing with bundles of rags it might get a less uniform look, more "naturalistic" - particularly if you use a few different shades in multiple applications that are not (each) covering the whole surface.

Answer 2

I haven't tried aging pressure treated wood before but when trying to match that grey aged outdoor look on non pt wood I use the following...

In a sealed jar like a mason jar soak some 0000 steel wool in white vinegar for a few hours or even da few days. The longer it steeps, the darker the aged effect will be. Rub the resulting liquid in to wood grain and let it soak in...

Some light sanding and rubbing of various objects like an old metal chain or even light hammer blows can also be used to make the wood look distressed and worn...

Answer 3

A hair dryer or heat gun applied artistically would have the effect. In movie making, lumber (and many other things like magazines and newspapers) is placed in an oven at moderate temperature to achieve the look of extreme age.

I would practice on a portion out of sight or preferably a scrap piece to learn the technique.

Answer 4

I think pressure treated wood is infused with copper these days. I would try ammonia, as its corrosive fumes can turn fresh copper finish into a nice petina within a day or so. The copper turns dark and eventually green too.

But spraying it on once probably will not do much. I would try a very light mist of 50/50 ammonia and water several times a day. Might work even better if you can contain fumes under plastic tarp or bag the wood for a while with some source of ammonia fumes.

You can probably accelerate aging, but nothing is likely to work instantly. So some patience is required.

UPDATE

Predictably, the suggestion didn't do anything, so I experimented and mixed Ammonia with OxiClean. Surprisingly, there was no reaction between these two cleaners and no noticeable pressure when mixing them.

Spraying this directly on the wood did seem to make the wood much more tan, but it did not cause the wood to appear any more gray. Not sure if repeated coats would help.

Answer 5

First, treated lumber is treated to prevent aging, so you will have better results with untreated lumber.

Moving along, you need to get some sulfuric acid drain cleaner (not lye). Make a 5-10% dilution of it (for safety- add acid slowly to ice water) and cover your porch wherever you want it to age. After a couple days, use a power washer (just a little too close) to help remove the softened grain. This will give the porch raised grains (as you ate away the softer bits).

Optional- for that extra-natural look you could also apply cellulase (online shopping) after acid etching.

Then you can stain it. It will look and act like it has been aged.