Exterior paint
clarkfamilyct
| Posted in Green Products and Materials on
We intended to use Safecoat for exterior paint, but our builder (who has never used Safecoat before) has expressed concern about its lack of fungicide and durability issues. For those who are familiar with Safecoat, what are your experiences with durability when compared to “low VOC” products from brands like Benjamin Moore. Is a fungicide necessary in exterior paint? We do want to avoid the need to repaint often and also don’t want to need to power wash the house with chlorox. Would these needs become necessary if we were to use Safecoat exterior paint?
Insight will be appreciated from those with experience in this area. Thank you!
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Replies
J.C.,
I've never used Safecoat exterior paint.
GBA readers: any advice for J.C.?
Also, any other suggestions for quality, health-safe exterior paint will be appreciated. We have cedar clapboard. I'm thrilled that I have located this forum, as we're hoping to learn from others' expertise and guidance. Thank you!
More important that what paint you use is making sure there is a proper rain screen under the siding. Paint will last a lot longer if any moisture that gets behind the siding can drain or dissipate.
My understanding is that some of the traditional pigments, like iron oxide red, inhibit mildew and rot. We've gotten used to choosing color based on other criteria, so that approach might not work for you (and it's hard to know how effective it is). But given how hard it can be to choose paint color, it might actually be helpful to have a functional reason to at least narrow it down.
Thank you, Charlie and Stephen. We are planning to use white paint. Does Safecoat appear to have the appropriate durability and properties? What type of rain screen under the siding should be used?
JC, if you're using cedar clapboards for siding, you can apply 1x3 or 1x4 furring strips over top of the housewrap before installing the siding. This doesn't add much cost but really helps the paint last much longer as the siding can more easily dry out when wet. Find all the details in Martin's article here:
https://www.greenbuildingadvisor.com/blogs/dept/musings/all-about-rainscreens
Martin, would you recommend back priming wood clapboards or cedar shingles if they're installed over a well ventilated rain screen?
I wish that I found this site sooner! The clapboard is already on, and they're waiting on our paint decision so that they can paint next week. The rain shield would have been great.
Does fungicide in paint offer any advantages? Should we use a traditional paint brand for the fungicide properties?
If your cedar siding is already on, why bother painting it? That's the ultimate in not needing to repaint!
Thanks, Nate. The cedar arrived with some type of primer already on it and is grey in color -- is that standard? We're looking to have a white home, which is why we're intending to paint. However, the builders also indicate that they feel that we need a fungicide and "durable" paint for protection on the exterior anyway. I'm trying to determine if it is accurate that cedar siding needs fungicide? Thank you for all of the insight!
J.C. I noticed from another one of your posts that the builder installed Benjamin Obdyke Home Slicker under the siding. That is designed to act as a rain screen.
Great, Stephen! Does fungicide in paint offer any advantages? Should we use a traditional paint brand for the fungicide properties? We are currently unclear about whether fungicide is necessary in exterior paint, or whether a fungicide-free Safecoat paint would be just as effective. We also welcome other exterior paint suggestions. What are recommended paint products by the experts in this Q&A forum? Thank you!
I think you simply have to weigh your options. Certainly a fungicide gives the paint the potential to last longer, but it's hard to know whether in practice it would be degrade by some other means first. The fact that you have primed cedar in a rainscreen assembly means you have the cards stacked in favor of durability already. You could conclude that you therefore want a durable paint so it's not the limiting factor, or that you can get away with a less durable paint because you have everything else aligned in your favor. An option would certainly be to use the Safecoat, knowing that it might need a fresh coat sooner. If you are unhappy with how soon that happens, you can be sure to use a different paint then.
Thank you, Charlie. Do you have experience with Safecoat and/or is it known to be less durable? We don't know anyone who has used it on the exterior.
Of the standard brands (i.e. Benjamin Moore, etc) what is the safest exterior paint? Are there any health or other issues to using a standard brand's low VOC product on the exterior, instead of Safecoat?
Thank you so much, Charlie. What nontoxic caulk should we ensure is used by our builders?
[Edit: added this first paragraph after figuring it out] It looks to me like Ben Moore Aura low VOC exterior paint and the Safecoat exterior paint are almost the same formulation, except that BM includes zinc oxide which inhibits fungus growth, as well as being a white pigment. I think that's pretty benign--it's the same stuff traditionally used as a heavy-duty sunscreen on lifeguards noses.
In general, I would vote for BM among major brands as having the best environmental policies and products, as well as for high-performance products.
I recently compared the "environmentally friendly" indoor paint offerings from Benjamin Moore and Sherman Williams. From what I could tell, BM has been a leader in making improvements, while SW has been trying to keep up and BM products go further than SW in reducing VOCs. There was also what seemed to me a stark difference in the tone of their rhetoric. SW emphasised that they have products that are fully complaint with whatever rules you might need to follow for a particular project. BM made it sound like they are serious about making products that are not harmful, including not only meeting requirements but looking for and correcting problems that are not covered by any rules or regulations.
I don't know whether BM is really running their business based on green values, or whether it is just that the folks in the marketing department know how to talk our language better than the marketers at SW, but I am sufficiently convinced that I would choose BM over SW.
BM doesn't actually include any of their exterior paint, even their low voc "Aura" line, on their list of products that meet all their criteria for being green. And I don't know why--maybe it's just that the zinc oxide's slight toxicity is too high for them.
Despite my interest in the question, I actually think it is relatively unimportant, both from a durability perspective and from a toxicity perspective. Getting flashing done right and done carefully is a much bigger deal for durability. And as one example of toxic materials, I recently looked at some ingredients on common caulks. The carcinogens in one and the endocrine disruptors in another strike me as much worse than anything in these paints.
OK, I should have known that you'd want to know about my caulk opinions as well.
For air sealing where it's not likely to be visible, I like Contega HF, imported by Four Seven Five building products. It's not low VOC, but the VOC is ethanol, so there's not much risk to human health as long as you don't swallow large quantities before using power tools. It's sticky and rubbery and a little messy to work with, and a pretty bright green color, so it's not really good for finish work, even though paint does seem to stick to it, so it could work OK in some scenarios.
For applications where it will be more visible, I think the Safecoat caulk looks like it would probably be good, although I haven't tried it yet.
Silicone caulk emits stuff you don't want to breath while it's curing, but once it's cured I think it's relatively benign, and it's highly waterproof, so I use that in some places as well, such as bathrooms.
ps Note that I added some more detail on the paint formulations in an edit of my comment #14 above, probably after you first read it.
You're wonderful, Charlie. Thank you!
J.C.
F.Y.I.- The primer that comes on the siding, is not intended to be left exposed for a long time. Many, many, many folks make the mistake of allowing it to lay exposed to UV and the elements for too long. It actually is supposed to be top coated within a couple of weeks of exposure, because it becomes chalky and reduces its adherence capabilities among other things.....
J.C.
Have you looked into limewash or milk paint? Limewash particularly is easy to make, allows the wood to breath once applied, is non-toxic and also inexpensive to make yourself (if you so choose). Just slather it on, and repeat as needed. It can also be used on the interior.
Old homes, when painted, were painted using lyme wash or milk paint like for years, and to make colors, either blood, or organic/earthly materials was used to change the color of the wash. Hence the common bucolic white farmhouse, or red barn seen all over.
Limewash does need to be applied more often than conventional paint when used on the exterior.....because it slowly washes away. The benefit to this, is that it can assist in amending the soil around your house as it washes away.
Good Luck!