STUCCO NEWS.NET

You may have seen this image on the September 2024 home page:

These specifications came to me in a bid invitation for stucco work on a historic church in Alexandria, Virginia. We did about $ 60,000 in interior plaster on this same church in 1996. I got bad vibes about this project and never estimated the job.

Our mixture for stucco is:

One 94 lb. Bag portland cement, or 2 cubic feet One fourth 50 lb. bag lime, or less than half a cubic foot. 20 shovels sand, or 4 buckets of sand, 4 cubic feet.

Sometimes, we use less sand for the scratch coat on metal lath ceilings, so not too much drips off on the ground. Sometimes we use up to 25 shovels of sand for new blocks that are rough and real porous.

Lime weakens the mix. Also too much lime delays the set, maybe for a couple weeks, and shrinks and cracks. I am positive anyone who writes specs like this has never put any mortar on the wall, or even seen anybody put mortar on the wall. Way too muck sand will slide off the wall.

This mix will never really harden and crumble easily.

Not as bad. I got these specs from a bid invitation fo renovating a historic courthouse in Virginia.

The base coat should read: One part portland, one-eighth part lime and 2 parts sand.

The finish coat has way too much lime. This will shrink and crack. In the old days, when they used lime and sand stucco, someone would wet the wall down probably at least 3 -4 days after applying, or rubbed the basecoat down for a few days to fill in the shrinkage cracks.

These are specs for replacing metal lath and cement stucco ceiling in a detention center. One part portland, say 2 cubic feet, 2-3 cubic feet of lime, and between 3 and 5 parts sand, or 12 to 20 cubic feet of sand, or about a half ton of sand. I doubt 5 percent of the scratch coat would stay on the metal lath. The worst thing is a ceiling would need to be plastered in a day, that is 3/4 inch of mortar done in the same day.

This is representative of all the misinformation circulating these days. It was bad enough before Google search was invented. We did a historic government job over 30 years ago, (It is on my stucco gallery), where I had to argue with government personnel over ridiculous specifications. It isn't worth the risk. Usually these specs aren't checked if it looks like you know what you are doing, but the work can be rejected. This whole bid system is broken.