# pressure treated vs. raw lumber for new painted ext. stair treads, what to use?



## jordanski (Dec 24, 2006)

hi guys,

any of you super experienced guys want to chime in?

built a new covered porch for amazing project, everything is real wood, super trimmed out and high-end work... the only thing left to do this year is to install & paint the porch floor and the treads and risers on the new stairs( the stairs are exposed and will see tons of foot traffic). I do all my own carpentry but originally a painter by trade

Currently the stairs just have temporary treads from leftover x4 stock just to last through the winter.

I will be painting the stairs with Cabot problem solver primer (oil floor primer) and water-based Cabot opaque color stain, with a traction admix for the treads. I'm gonna stick with this as it has done me well in the past.

as for the treads, this is the first time I've done them outside, seattle gets a ton of rain, and either way they will get prime/paint on all four sides.

my install will be: prime and paint boards, cut & install with deck screws, countersink & putty, touch up putty and cut ends with primer/paint... done

the treads will be x4 dimensional lumber so what will work better? raw fir or pressure treated? money is tight, wrapping this project up and been working on it since sept '07... 

I've got an old school paint sales rep with a ton of exp saying pressure treated and a master carpenter telling me regular wood... any of you old school cats from inclement weather country care to chime in and help?

btw - pressure treated would be appearance grade (most yards here call it Sunwood) which is much more expensive than regular old fir...

thanks in advance
jordan


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## BuiltByMAC (Mar 11, 2006)

jordanski said:


> the treads will be x4 dimensional lumber so what will work better? raw fir or pressure treated? money is tight, wrapping this project up and been working on it since sept '07...
> ......
> 
> btw - pressure treated would be appearance grade (most yards here call it Sunwood) which is much more expensive than regular old fir...



Sunwood, aka DuraDek, is a surface treated hem fir, not pressure treated. No cleat marks - just a wash that's applied to the surface. My first deck was a little 8x12 nothing w/ DuraDek on it...stuff looked like hell after a season. Once the treatment started flaking off, you would need to sand and restain for it to look good. 
With untreated fir, you can at least build up the layers of stain and have a longer-lasting installed product. With army boots 'n teenagers, the surface will get beat up. Period. 

In your other thread, you talked about this staircase being 10' wide. Do you have intermediate stringers or is the riser/tread connection spanning that 10'?

What's your attachment method for treads to stringers - dadoed notches in closed stringers or metal 'L' brackets?

Mac


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## jordanski (Dec 24, 2006)

*clarification and question*

Hi Mac,

You're absolutely right that sunwood doesn't have the chemical injection process, just a covering of the same chemicals, I really like using it on posts and such that are somewhat covered, like under a deck, and have had luck using it on a railing for a wheelchair ramp-like deal, held up pretty well.

I used regular pressure treated for the stringers and puttied the stamp marks on the outside face of the two ext. risers for aesthetics... and yes there are stringers in the field, I widened the stairs as much as possible and ended up with an odd width due to where I could sit them on the existing concrete, but the stringers are within code, don't remember exactly but something like 20' O.C.

Originally each stair was gonna get the same fir TNG boards with a bullnose to match the porch floor but after seeing the number the kids did on the temporary treads in six months (cigs, skateboards, boots, etc.) I decided to just go with something solid, easy to touch-up with epoxy putty and paint for ongoing maintenance, and simple to replace if necessary.

As for installing treads to stringers I was just gonna do a screw and glue, which works fine and easy to cut out and replace if necessary.

Your idea of a notched dado cut kinda saddle fit seams like it would be really hard on 10' wide stairs... the lumber is gonna have a little bit of twist, that sounds like some crazy spiral staircase type super high-end business! I'm gonna keep it simple but more power to ya if you can do it that way quickly. I was gonna set treads and risers in place with a couple finish nails then use deck screws on treads (bead of subfloor glue on the stringer) and those small head stainless hardwood screws on the face of the risers... epoxy putty fill on the countersink and done in a day or less...I'm not a master carpenter but this to me seems sound...remember it's being painted...

back to the tread issue, to me it seems rational that the oil primer would penetrate better on raw fir and last well if I back-prime the underside. I was gonna cut everything a few inches long and totally pre-paint at home, then install, quick primer the cut ends and touch-up the paint/color stain (front door access only down for one day that way).. I was surprised my sales rep (who is a super knowledgeable older guy and ex-painter) recommended the sunwood. It is like double the price and probably needs to cure for a while before painting. Kinda why I was thinking about this a bit in advance. It snowed baseball sized flakes here today followed by a massive windstorm!

You're right I'm probably hosed and will have to resign myself to beat-up looking stairs in a month or so and yearly touch-ups...

Had no problem painting pressure-treated before but used 24 hour oil primer and not on a walking surface, the cabot is like a 4-8 hour primer so maybe not a good idea on the sunwood as it would have to penetrate through the chemical wash... I don't think it would matter if it were a post or something else without foot traffic.

So long story short, would you agree then raw fir dimensional treads with primer coat on all sides would be the best route? sounds sturdy to me...

jordan


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## BuiltByMAC (Mar 11, 2006)

jordanski said:


> the treads will be x4 dimensional lumber so what will work better? raw fir or pressure treated?





jordanski said:


> but after seeing the number the kids did on the temporary treads in six months (cigs, skateboards, boots, etc.) I decided to just go with something solid, easy to touch-up with epoxy putty and paint for ongoing maintenance, and simple to replace if necessary.
> 
> back to the tread issue, to me it seems rational that the oil primer would penetrate better on raw fir and last well if I back-prime the underside. I


For some reason, I was thinking x4 meant 4x, meaning your treads were 4x10s or 4x12s. I've built stairs like that before (just not w/ a 10' span) and that's why I was asking if there were intermediate stringers and what attachment method you used.

OK, 2x4 treads w/ stringers 20" oc - now I'm on the same page.

Regarding painting the treads, every deck surface I've seen that was painted...peeled. Badly. Paint was not meant to be walked on. I was suggesting a penetrating *stain* for your treads as it will protect the boards better. Once the paint on the treads wears or splits or flakes or peels, the raw d. fir will be exposed to water (and water will get under the remaining paint and rot out the board too).
Now, having said that, I'm not a paint guy. There may be some paint/primer setup out there that would work perfectly. I just don't know what it is.

Good luck, and post pics when you get it finished!

Mac


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## Chris G (May 17, 2006)

I use raw wood when the stairs are going to be painted. Pressure treated is just fine too, as long as it's had some time to dry.

I have been told by my paint suppliers and manufacturers, to NOT prime stair treads. The reason being is that is will make the finish coat sit on top. This is good for interior stairs that are locked in and not prone to movement and humidity cycles. But that hard surface layer that you have created by priming will start to crack and flake over time on an exterior stair that is more likely to "move".

You will need to paint every year regardless.


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## vandyandsons (Dec 23, 2008)

use raw lumber if you want to paint it this year!


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## jordanski (Dec 24, 2006)

*last words*

I'd say raw wood it is. Issue settled.

One last thought for others who have to paint pressure treated wood...

If it's an existing structure that some carpenter just built or your lumber is fresh out the yard you do need to check it with a moisture meter before painting as the wood is treated while green and doesn't dry much wrapped in plastic sitting on a pallet. In my exp it takes a couple of months minimum drying on a shop rack inside to get the average board down to 11% percent moisture i.e. paintable...

Finding out the deck you just painted was sitting in a forest two months ago is a bummer of a problem after you've painted... bubbles!
J


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## DecksEtc (Oct 27, 2004)

The drying time for PT really depends on the location of the wood.

Southern exposure with a ton of sun might be a month. If it's really shaded it could be 6 months or more.


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