|
Posted by James \"Cubby\" Culbertson on July 30, 2006, 11:22 am
I'm no expert but here are a couple observations I've had. Stucco cracks.
Period. It is in fact not a real good outside material due to it's low
permeability but it's used extensively in the West (it's on my house).
I've no experience with just painting it but it seems to me that would
decrease your permeability even further and increase the risk of moisture
damage in the home. I could be wrong on this point, perhaps there are
breathable paints out there but not sure how they'd do sealing cracks. For
cracks around here, I see most people opt for filling them in with mortar
and then color coating them. If you can get a good color match, they
usually don't look too bad when dry but after a rain, you can definitely see
them. The other option would be to color coat the entire house
(expensive!). I'll be watching this thread with interest to see what the
experts have to say.
Cheers,
cc
> My 3-coat unpainted fairly rough texture stucco is 15 years old and has
> a lot of hairline cracks (less than 1/16") which isn't surprising since
> I live in earthquake country (Northern California). In one place next
> to a window, enough color coat has chipped off so that I can see the
> crack goes into the brown coat.
>
> Since I'm worried about water penetration (a neighbor has measured
> gusts of 87mph and rain sometimes seems to be horizontal), I'd like to
> repair the cracks. After talking with a number of people and doing web
> research, I ended up with lots of information but no consensus on how
> to do the repair.
>
> I've summarized my findings below and would appreciate comments
> regarding pros and cons that are based on actual experience. Thanks in
> advance.
>
> There seems to be two general categories of repair, cement/stucco based
> and paint based, each with several variations. References are marked
> with a number in brackets, e.g. [1] and are given at the bottom.
>
> Remember the below is only for hairline cracks.
>
> 1. Cement/stucco based repair
>
> Advantage: Still have low maintenance stucco finish
> Disadvantage: Repaired cracks will almost certainly be visible
> Options 1.1 and 1.2 are similar but slightly different.
>
> 1.1 Mix portland cement or stucco with half-and-half acrylic modifier
> and water. Apply with putty knife. Work to match texture. Apply fog
> (color/finish) coat afterwards. No need to widen cracks. [1]
>
> 1.2 Apply a acrylic multi-bond (green from one vendor), let set 34 to
> 45 minutes, apply a one-coat stucco matching texture, apply fog coat
> after a couple of days. [2]
>
> 1.3 A variation of 1.1 and 1.2 is to apply a new fog coat to all the
> stucco, not just around the cracks. This "should" make the cracks more
> invisible than any other method. I'm not sure how well this will work
> over my rough texture. Seems like this might also be a relatively high
> cost option. (Can't recall where I heard of this alternative.)
>
> 1.4 One stucco person who covered a small addition for me a few years
> ago, upon seeing I had some old color coat mix (left over in a bag) and
> a stained area of stucco, suggested I could take the stucco mix, add
> water, strain, and spray the "colored water" onto the stucco. I wonder
> if this would work to make the color uniform after 1.1 or 1.2? Also
> this sounds expensive (and a waste) to buy new stucco mix to do this to
> the whole house.
>
> 2. Paint based repair
>
> Advantage: Finished job will be uniform color, possibly hiding
> cracks
> Disadvantage: Now have a painted surface to maintain/repaint.
>
> Common: Fill cracks with Elastomeric Sealant (brush grade) or perhaps
> latex caulking.
> Still need to match texture, given recommended 2" width for
> sealant,
> so patched cracks might still show through new paint coat.
>
> 2.1 Paint with Elastomeric Paint [3]
> Advantage: Some stretch to keep very small new cracks from
> showing.
> Disadvantages: Costs more than regular paint per gallon and much
> lower coverage.
> Reports it is harder to apply than acrylic latex
> paint.
> Reports that it creates a vapor barrier which can
> cause problems
> if moisture gets trapped behind.
> Notes: Manufacturers have different recommendations for number of
> coats.
> Need to monitor application thickness.
>
> 2.2 Paint with Acrylic Latex [4]
> Advantage: Less expensive, easier to apply. Does not create vapor
> barrier
> Disadvantages: May not have stretch to cover new cracks.
>
> [1] John J. Bucholtz, "The Consumer's Stucco Handbook" (30 page
> pamphlet)
> [2] advice from Stucco Supply store
> [3] "Kel-Seal Elastomeric System, a Technical Guide to Elastomeric
> Applications"
> (9 page pamphlet picked up at paint store)
> [4] Suggestion from paint store and several news group web postings
>
| 
Yahoo! 
Google 
Windows Live 
del.icio.us 
digg 
Netscape 
XML Sitemap