Paint On Cedar Siding Peeling.

I have a customer with some old cedar siding that is suffering some peeling issues. She has recently put an addition on the house with new cedar and after letting it age she has primed it and some of the existing cedar with a good oil based primer and coated over it all with a waterborne house paint. However both the new and old siding has paint peeling where the end joints of the wood butt together. This is clapboard siding I believe. Normally I'd suspect a moisture issues but the inside of the house is undergoing renovation so all the drywall is torn out and the back of the siding is completely exposed to heat and airflow. There is no apparent moisture on the inside of the siding. This peeling occurs just a couple months after painting. I'm thinking of thinning a good oil primer down with penetrol for deep penetration and telling her to coat over it with a good flexible acrylic, but this is so similar to what she has already done that I'm afraid she'll run into the same issue. Any input would be appreciated.

Possible mill glaze being's its cedar siding maybe?

Finish Applications
Paints will perform best on clear (free of knots) edge-grained cedar. However, cedar with tight
knots can also be painted successfully, especially the rough sawn surface versions. Solid-color
stains are often chosen as the best finish for the rough sawn cedar surfaces. If smooth cedar is
used, research has shown that scratch sanding the surface with 50–80 grit sandpaper will
improve paint adhesion and paint performance significantly without affecting the final
appearance. Research has also shown that cedar should not be weathered before painting
because weathered cedar surfaces are prone to early paint failure. Power washing should never
be used before finishing or refinishing cedar because this process can severely damage the wood
surface fibers and make it difficult for the finish to adhere properly.
When applying paint and solid-color stains to previously unfinished cedar it is very beneficial to
apply one coat of primer paint to the back (sometimes called back priming), edges and ends of
siding boards before the cedar is installed. Back priming helps reduce wetting up the back side
of the siding. Coating the ends and edges helps prevent water penetration in those areas. It’s
always important to remember that good finishing practices, proper siding installation and proper
siding venting are a necessity for good cedar performance and for the longest lifetime for the
finishes. Applying the finish by brush is usually the best procedure to use for the best durability.

Also, use the best quality products available, oil based primer should dry at least 48hrs,
unless you use the quick dry stuff (not my favorite) and 2 coats of 100% acyrlic exterior paint
(California Velvet Flat is my choice). Butt end joints should be caulked to halt absorbtion
of water.

What "waterborne house paint" did she use??

Hmmm...I see that all the time on no-primed clap
...and Behr painted clap
...and sprayed no back brushed...
...and painted over mildew...
...and "wet" houses (former summer houses over winterized w/all the vents plugged up and leaching moisture from the inside out to the siding)

Easy enough to check moisture issues with a $35 meter

Rather than thin a good oil primer to get it to penetrate, maybe try Ben Moore's Fresh Start Penetrating Oil Primer

Need to stick a meter on it to discount the moisture thing though
If it's a wet house then a latex solid stain and prayer is the best bet

I'm not a painter but I do install lots of prefinished cedar and fibercement siding and I know that none comes with paint. It's all stain. Also in everything I have read, it's said not to PAINT cedar because due to the natural tannis (resins/sap) in the cedar the paint is likley to blister and peel off.

Just this siding guy's opinion. Don't paint cedar. However I am sure some painters think I am nuts and sitting at their keyboard laughing at me.

HaHaHeHeHoHo...
More than likely the pre-finished siding comes with a solid stain [which is basically a thin paint]. Solid stain is film forming, and requires a stain blocking primer [oil: good or acyrlic: better durability]. Tannins /resin/sap have nothing to do with blistering paint or poor durability, however they will cause a surface problem in the form of brown stains leeching to the surface.
I expect paint to last 10 years on a properly prepared surface [inc' red cedar siding]. Nothing wrong with paint on cedar siding whether its smooth side [sand with 80 grit to remove mill glaze] or rough side.

Thanks for the laugh :-)

I haven't gotten any more info from her yet. We've called her a few times and she has never called back. Either she found her solution or decided not to worry about it at this point. We were going to go out and look at the house, test it for moisture, etc. But I guess we'll have to wait on a call back now.

Thanks for the input.

That goes against everything I have read or heard, however I differ to your expertise. I shall try to find some of what I have read saying not to paint cedar.

I'm doing a cedar lap sider right now. Pics below show a tannin bleed and an after . I power washed with bleach and regular tsp to get more bite for the sw duration satin. Then an exterior stain sealer on the tannins.
It looks pretty shiny for satin, but that's my camera settings, which I haven't mastered yet.

My view is that properly prepped and painted new cedar will still have tannin bleed until the second paint job. This one was already painted and no bare wood for the bleach to ruin.

Power washing isnt the best practice, you introduce water to the backside of the siding, this will encourage the tannins to leech. If you look at the North side of the house you will often see that most of the bleed through appears there. The North being the coldest side of the house attracts the most moisture.
I use a power washer to rinse the surface with clean water 500p.s.i, the cleaning is done with a bristle brush and elbow grease.
I'm confused about the statement " This one was already painted and no bare wood for the bleach to ruin "
That implies this is the second paint job, and unfortunetly no amount of paint will stop the bleeding if moisture is present and back priming is not. Often have the same problem, I can halt the stains using an oil stain blocker, but teardrops appear underneath the siding edge. Lucky these disappear after a few warm days, but the first time I saw these I thought I was in big trouble.

What do you think about the Duration Paint/Stain? Read their info and it seems similar to Cabots Pro-Vt.

Just gonna jump in on the prep and toss my peanuts in from the upper balcony. Cedar should be cleaned with a mildewcide like sodium percarbonate and then pH balanced with an acid to prevent/slow tannin and extractive bleed.

In my opinion, no wood should be painted, ever. Too many issues with moisture. I'm not saying it isn't done or that some guys haven't had success painting it. Cedar is a soft, high expansion wood. The prep has to be very good for paint to stick to it. In this homeowner's case I am going to venture that moisture content was the culprit.

Those are knots that are bleeding - nothing will stop that - other than painting with a dark color, so you don't notice bleed, or spotting with shellac.

Up in the northeast, all homes are painted, and they consist of 95% cedar shakes or clapboards. The proper way to paint - is first to install factory primed siding - let it weather for 10+ months so the extractives deplete themselves. Pressure wash with Bleach & TSP, if not going to use high pressure - then scrub every sqare inch. Rinse. Let dry - for as long as it takes - some homes I have had to wait a month before all moisture left. Then reprime with a quality long oil primer, caulk, seal knots, then paint two coats. The first latex coat can be another latex exterior primer for an even higher quality finish. On new wood - this job will last 10-15 years.

To answer, I learned in this forum that bleach isn't the best cleaner for bare wood. Yes this is the third paint job on this home. First was new const., second was done 7 yrs. ago by college painters and now me. Tannin bleed is all over this house, north side is no worse than the rest. If a home has enough ventilation there shouldn't be a problem with trapped moisture, although, I agree that the north side is the one to watch in that respect.

The only reason I used bleach and regular tsp was to kill mold and create a bite on the old satin paint, so I don't have to prime. This probably wasn't even necessary with duration, but I'm also painting the gutters and downs. So I used a really strong solution of bleach and tsp on them to etch them. The gutters and downspouts are the only areas I hand washed in addition to using the power washer. Does this make sense? In your world of restorative painting, I can see why you take that approach, but on this house, I'm pretty sure my job is going to last a hell of a long time.

I keep forgetting to mention that I AM spotting every dang tannin bleed with shellac based, spray can primer. Just didn't get a picture up at that phase.

I like duration, good paint. Medium to light colors are easy to work with. Deep tints make it very, very thin. I'm using a deep color on the shutters. You just use it like any thin paint and it works fine. 2coats, no problem.

Hope this answers your post, and if not maybe I can learn something too.

Heck, I may as well add something else. This is a long time customer's house, I always told him it's best to paint in the fall (chicago area), because there is much less humidity. Things dry out fast. I waited almost a week from powerwashing to starting to paint. Not that I was waiting that long for it to dry, I just has other things to do, but that amount of time, at this time of the year pretty much guarantees a good, clean, dry substrate to work with.

Good to hear experienced pro's exchange info. Miss the pub where you'd normally learn these things. Pint for anybody visiting the Hudson Valley.

Cheers to All

I have never seen paint hold up on cedar, for the reason that paint gets harder as it drys over time, stain just changes the pigment of the wood, also it soaks into the wood were paint lays on the surface, So I have always said to people they should stain it over painting, But if they want paint and they are paying for it then if it peels it will be touched up but they will be billed for my time. Cause that's the nature of the beast.

Paint versus Stain on cedar siding.
I mostly do restorative exteriors, which is the complete removal of paint from the siding, sand, oil prime and two top coats of latex 100% acyrlic. The majority of the siding is western red cedar and because these homes are 50+ years old the siding is from old growth. I warranty all my restorative exteriors for 10 years, which means if there is any peeling/paint failure due to poor preparation, workmanship or materials I will provide labour and materials to amend the problem. I encourage all customers to investigate the paint [film forming] versus stain [penetrating finsih].
If the mechanics of the house are not in good order [ventilation, gutters, damp basements, roof, etc] and they will never be in good order then stain has an advantage in that it will allow moisture to travel through without causing finish failure. However, paint will provide protection for 10-15 years depending on exposure to Sun, house mechanics, whereas Stain will last 3-5 years. True stain will require less prep work when it comes time to re-stain, but if you paint before failure there is also less prep work.
Newer construction often has new growth lumber which is inferior by far and will fail more often if good install practices are not applied: Factory primed, or dip in water preservative on site to seal all surfaces, sealing cut ends, rain screens, proper nailing, etc.
Again, in the market cost determines finish and "Joe Builder" will often apply a stain cause it won't fail.
There will be diehards in each camp, what the customer wants and can afford should determine the finish. I can only inform and over my advice and experience, eventually I'm "Just the hammer that knocks the nail ", but I do walk away from the wrong nail jobs.

p.s. Interested in the apply oil then acrylic primer method, haven't come across that one. Can you provide a source for the background on that?
I defer to the "Forest Products Society" and "Western Red Cedar Association" for info.

The best primer for cedar is California troubleshooter primer. Used it many times and had no issues of peeling.

Peel Bond is also an excellent primer for cedar. Providing that there is not an underlying moisture problem, Peel Bond will penetrate and seal cedar. The biggest advantaged is that Peel Bond will breathe unlike the oil based primers. Tannin Bleed can be taken care of by adding Bleed Control to either the primer or paint

Another thing you have to realize, especially with smooth sawn clapboard is that the factory primed stuff has been pretreated with acetone or something so that the primer has 'bite' into the wood. Where as they do nothing with cedar that isn't factory primed. So as my experience so far has indicated with everything from siding to decking - is to either abrade or chemically 'age' the wood before priming. I have had to clean up interior poplar trim because it was so badly mill glazed with acetone prior to priming - so the paint would hold. I have done some jobs where the cedar was several years old - and even though bleach isn't the preferred cleaner - I used a combination of bleach/TSP/surfactant and scubbed the surface vigorously an then pressure rinsed to get rid of all the mildew and aged wood. And then used a quality oil based primer - and all has been well. Another thing of note - manufactureres recommend priming all the cuts - with clapboards this is essential - they should prime their cuts and nail on while still wet - so all 6 'sides' of the clabboards are sealed - this will prevent egress of water at the butt joints.

Tommy, Looking at those pictures, are you showing the finished paint job first, and the installation / prep second? Were those shingles installed new or stripped? That looks like a wagner paint eater on the ground, have you found that usefull on cedar shingles? Thanks!