All of the cold weather here in Minnesota is leading me to think of warm weather projects. One I’ve been considering is limewashing the stucco on our 90-year old bungalow. The stucco is in good shape (no significant cracking or other issues) and has not been painted. It is a very light tan color, but we would like to freshen the color and (maybe) shift to a slightly darker shade.
Do you have any experience with limewash? I’m particularly interested in learning about it’s application (can it be sprayed?) and the costs. Any recommendations on limewash manufacturers (I know of Porters and US Heritage Group)? What is the difference between fog coating and limewashing?
Thanks in advance!
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I'm in Minneapolis. A few years back a friend of mine had the stucco on her house fixed up by Donnelly Stucco. They repaired some cracks, and then they changed the color by putting on what they called a 'dash coat'. My understanding it was sort of a thin, wash coat of fresh stucco over the top, and as I recall it didn't take them very long at all to do the entire house. The advantage is that it was a permanent color change - she had no worries about maintenance or having to repaint or re-limewash in the future. Once you paint it, you have to keep repainting it forever.
Edit: there are several stucco companies with similar names around here: besides the original Donnelly Stucco, then there's a Donnelly Brothers Stucco, and there's an Ed Donnelly Stucco. They're all from the same family, various brothers and cousins I think, who have split off from the patriarch over the years.
Edited 1/26/2009 8:17 pm by Stuart
Edited 1/26/2009 8:18 pm by Stuart
I have heard good things about the various Donnelly stucco businesses. One concern I had about redashing is added height of the stucco compared to the window and door trim. I looked at one redashed house where the trim was essentially sunken or flush with the stucco and I didn't care for how it looked. I don't know if that is a common issue or specific to that house. Did your friend's house have that problem?One thing I like about the idea of limewash is that it is something I could potentially do and (I suspect) less expensive than redashing. I'm on the southside. Where are you in Minneapolis?
As I recall the dash coat on her house really didn't add much thickness to the walls at all - it was more like a heavy coat of paint than anything. I believe they put it on with big heavy duty brushes, it wasn't troweled on. The trim wasn't recessed, at least as far as I could tell.
I'm in the Whittier neighborhood, a few blocks west of the Institute of Arts.
You can put on a very thin coat of stucco, if the mix is right.Portland Cement website has good info.
Good to know. The trim issue I saw on that particular house must have been unrelated to the redashing. I'm in Central on Portland.
Some parts of the world call that a "fog coat."
I did a version of this last spring on a small addition. There is a special color mix that has virtually no aggregate in it. It's called a Fog Coat Mix. I believe it is a mix of lime, white portland cement, and whatever pigment is chosen. Usually guys spray this on with a special machine. Since I didn't want to hire that out or rent the machine, I simply mixed the fog coat mix with water until it was a thin pancake batter consistency. After wetting the stucco, I brushed this on quickly with a big 8 inch limewash brush. It has rather stiff straw colored bristles. I forget where I bought mine but I imagine a supply house with stucco and plastering materials would carry it. At any rate, it worked out well. In my case the stucco already had a very rough texture so whatever texture the bristles left didn't really matter. If you have a smooth or consistent texture to your stucco, you probably should have it sprayed. Also, this is meant to bond to unpainted stucco. I think you'll have problems if there is a layer of paint.
It sounds like traditional limewashing does not include the portland cement component of fog coating and that a fog coat mix will be somewhat thicker. Is that right?It makes sense that you would want to mix up a single large batch of either to ensure color consistency. Any idea on the pot life or working time of a limewash and a fog coat mix? Do you think limewash could be applied with a good compression sprayer? What about a fog coat mix with an airless paint sprayer? Or would the solids be too large compared to paint solids?Thank you for the info so far. It's greatly appreciated!
Traditionally Limewash was applied every year. So that's
something to consider. All the talk of sprayers is a bit out of line with the idea
of being able to slap on a coat with no need for particular care,
or skill.
Limewash wears that quickly? Good to know.I'm not sure that I follow your second comment. I'm wondering if limewash and fog coat mixes can be applied with readily available sprayers or if it requires specialized equipment. But regardless of the method (brush or spray), I will take great care in my preparation and application. Which is why I am asking so many questions beforehand.
I'm not saying it will need repair every year, rather
historically that was the method. If you look up Cob houses you'll find a long
European history of Limewashed homes. The Lime stuccos have lasted centuries with regular
limewashes. The second part was referring to that same history of
frequent but very simple malignance. Often the simplest
methods are the best.
Lime-wash is a sacrificial coating. Basically, you're allowing a thin layer of calcium-carbonate (or Mg, in some some mixes, I think) to crystallize on the surface. The crystals are what gives the lime wash its refractive brilliance. At the same time, because it is basically limestone, things like acid rain will wear the coating down, but it's a simple process to restore the coating by simply recoating it. I don't even think many people wash it beforehand. Eventually, the layer would build up and create a thick, but extremely vapor permeable coating. Lime wash, as long as you've got in a sealed bucket, should last pretty much forever. Just mix it up well when you use it again. Anything with portland cement will have a shelf life probably in the hours once mixed. Portland cement cures chemically, where as lime wash works through carbonation (absorbing CO2 from the air). Z
I'm going to look into lime paint, but it sounds like we should probably have the stucco redashed/fog coated rather than using a traditional limewash to achieve the effect we're looking for. Thanks to all for the help. It definitely cleared up some of the confusion I had.
would it be beneficial to use a concrete stain instead of paint?
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The application of Fog Coat can be done with a brush and water. The "Special" machine to do it with is call a "Hudson Sprayer" The mixture is very watery and is usually strained thru a sock into the container.
When sprayed thru a Hudson sprayer a 25 lb $15 bag will do up to 1000 sq ft. The coverage depends on whether the mix is like milk or like pancake batter.
I experimented with lime-wash on my garage. Mixed up some masons lime in a bucket, and slapped it on with a lime-wash brush (also found at the masonry supply store). It doesn't look like much when you put it on, but by god in a couple of weeks it turns into a solid brilliant white like you've never seen. It appears to be fairly robust and you can use concrete pigments to color it, though from what I've read you need to keep the wash well mixed and you should mix up enough for the entire job at once since the color will be hard to duplicate in separate batches. If you've got kids, it'd be a great project for them, just mask everything well, and let them go to town, the messier the better.
Z
I am reading about limewash then Portland cement. They are two different things.
Go to http://www.virginialimeworks.com and discover the advantages of real lime.
Lime can also be used as an interior paint, it has a higher refractive index and gives a spectacular finish.
Thank you for pointing me to that website. It has a lot of good information, especially for the preservation minded.