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Rolly / Moderator

Feb 1, 2003, 2:19 PM

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House Project Update for 01 February 2003

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We got started on painting the outside after recovering from problems with the sealer/primer we sprayed on the stucco last week -- details on the website.

Coco finished the windows in Andrea's house -- 2 done and 2 to go.

We hired another cabinet maker to speed up that work. We now have two guys building cabinets and closets. We are looking for another one to make the interior doors; we have 19 of 'em.

We took delivery of the floor tiles -- 500 boxes of title. After the ladies spent some time looking at the tile, they changed their minds about the wall colors they chose last week. More on that later.

Check out this week's work at: http://rollybrook.com/02-01.htm

Rolly Pirate

Gary sculptari

Feb 1, 2003, 3:45 PM

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Re: [Rolly] House Project Update for 01 February 2003

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Its too bad I didn't think of this before - here is a recipe book for the lime paints/whitewash from the 40's or 50's that a fellow plasterer is hosting for me:

http://www.battersbyornamental.com/wallerlime.htm

The advantages of whitewash is that it kills all the molds/germs/ when it is applied, but it takes many years of application until it builds up a nice thick hide. Bugs seem to hate it too. I also have source of lime proof pigments to get those bright colors you like so much. A lime paint or whitewash allows the wall to move moisture through, which is especially important in a new building. Latex plugs it right up until it peels off - it never really becomes a part of the wall, just sits on it.

These paints went out of style when retailers found they preferred selling a $30 gallon of 'wonderpaint' rather than $5 for a fifty lb sack of hydrated lime. The lime paints are making a strong comeback in both the 'designer' markets and the 'green' construction markets.

Feb 1, 2003, 8:07 PM

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Re: [Gary sculptari] "Green" Product??

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Gary "sculptari" writes:
....The advantages of whitewash is that it kills all the molds/germs/ when it is applied, but it takes many years of application until it builds up a nice thick hide. Bugs seem to hate it too.....

On the whole, whitewash will have roughly the same effect on molds, fungus, bacteria, and insects as any other surface coating (paints, shellacs, varnishes, etc.), mainly separating them from moisture, light, air, or other environmental components needed for growth, as well as both sealing cracks and surface imperfections where growth could occur and creating a surface where growth can be more readily observed and removed. In this sense whitewash is inferior to other coatings as it has limited cohesion and doesn't form as much of a barrier as other coatings. Because of its high pH, the principal ingredient of whitewash, calcium hydroxide will have a greater effect on selected bacteria, insects, and active mold and fungal growth, if there's sufficient contact time before the whitewash dries.

Where you'll see significantly enhanced biocidal properties is in the "specialty" whitewashes (there were several in the pamphlet you provided a link to) to which a considerable quantity of formaldehyde is added. Although the formaldehyde is undoubtedly used to combine with the casein also used in these formulations to form a polymer, sufficient free formaldehyde would be present during and after applications to act as a powerful biocide on treated surfaces. Unfortunately, since the preparation of the pamphlet in the 1950s, formaldehyde has been indentified to be a suspected human carcinogen, and is regulated as such by even the most conservative of regulatory bodies such as OSHA. In addition to significant exposures that could be expected during mixing and applying of formaldehyde-containing whitewashes, you could expect residual airborne exposures when such materials are used indoors as (a) formation of the casein/formaldehyde polymer would be incomplete because of the primitive reacting conditions, and (b) additional releases as the polymer deteriorated. In addition to issues surrounding carcinogenicity, before most construction-related uses of formaldehyde were phased out, formaldehyde was considered to be a significant contributor to indoor air quality problems.

(This post was edited by ET on Feb 1, 2003, 8:09 PM)

Gary sculptari

Feb 2, 2003, 11:41 AM

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Re: [ET] "Green" Product??

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Edgar, you spent your Saturday night scouring the internet for 'the dirt' on this whitewash post?

Once again, what you came up with is wrong. Firstly, lime does not 'dry' or 'cure' like other paints, it is unique in that it recarbonates, taking carbon dioxide from the air, and turning the calcium hydroxide to calcium carbonate. Moisture does not dilute the matrix, it merely retards the recarbonation, so this is why whitewash is so good in moist areas. And yes it does not form a barrier or seal, the current thinking with building technology is that seals can be a bad thing, a building has to breathe - do you have any idea how much water vapor is generated within an average human occupied building - it is staggering. In Rolly's project the walls and ceiling are like a giant sponge, taking in and giving off water according to climate/humidity. To say lime has 'high ph" is an understatement - it is highly alkaline. With regards to the formaldehyde, I don't think the booklet suggests that recipe for this job, and even if it did, I imagine Rolly would have a harder time finding casein powder than formaldehyde or the host of other products of this type.

In real terms, I think the disadvantage of whitewash is that for the first few years at least, it has to be painted every year -but then again it is very inexpensive and can be quickly and safely sprayed by semi-skilled labor. It also has a lovely smell - like fresh corn tortillas I think. If you do not get around to repainting, it seems to slowly and naturally wear away. The synthetic based paints look great to start, and then start to fail quickly and dramatically, often peeling away in sheets. The alternative 'paint' for a job like this is the so called 'mineral' paints, based on potassium silicate - they have been well proven for over a hundred years in Europe by companies such as Keim. I make my own mineral paint, maybe I should sell it in Mexico.

(This post was edited by jean on Feb 2, 2003, 2:15 PM)

Feb 2, 2003, 3:30 PM

Post #5 of 5 (1186 views)

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Re: [Gary sculptari] "Green" Product??

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Gary,

In reality, the only web page I hit before starting to write was the one for your 1950's whitewash pamphlet.

What I do believe in doing, and what I find to be considerably more intellectually stimulating than jigsaw puzzles is to actually read other people's postings and think my comments through a bit before I start flailing away at the keyboard. If you had done the same, you might have noticed that my comments were made in response to your assertion that "The advantages of whitewash is that it kills all the molds/germs/ when it is applied". Nothing in your latest reply serves to support this assertion or refute my comments.

It is not automatic or by definition that you need your building surface treatments to breath. Instead the underlying construction materials and techniques, the type and quantity of ventilation used, and the overall integrity of the building envelope would all come into play. Premature failures in surface treatments can be the result of improper matching with these factors, or simply poor preparation and/or application of the treatment, and can occur with any material, whether it is a "synthetic based paint", your good old-fashion limewash, or your "mineral" paints.

If it's being applied for protective, rather than strictly aesthetic considerations, the durability of whitewash is far more of a consideration than you make it out to be. Actual water (not to be confused with moisture) contact such as with rain affects whitewash a good deal more than your "synthetic based paints", and while "it seems to slowly and naturally wear away" the bottom line is that when this wearing away occurs the underlying substrate is unprotected, just as in the case of the synthetic based paints if and when they dramatically fail. And even in Mexico, where your labor costs are dramatically lower, both the dollar and hassle costs (finding a painter, surface prep and protection, and either constructing scaffolding or having a painter hanging around the house on a ladder for days on end) of annual applications of whitewash can easily eclipse the cost of applying a coat of the appropriate durable material every 3-7 years.

In summary, I don't believe whitewash to be the absolute or perfect solution to every construction need.

PS - Your statement "To say lime has 'high ph" is an understatement - it is highly alkaline" is an absolute keeper.

(This post was edited by jean on Feb 3, 2003, 6:12 AM)