Master of Plaster Q&A

Still working with MOP

Steve O — Fri, 16 May 2008 01:22:11 GMT

Hey all, great forum. I have experience with 2 other Italian plaster manufacturers and MOP is different from both, especially the venetian plaster. In the italian plasters you use the same plaster for all three steps.

Now MOP requires two base, then the finish over that. I have noticed a considerable ammount of drag lines and chatter whenever I do the second base coat. I thought it was self leveling. The chatter is showing through the finish. What do you do to get rid of the chatter?

cracked plaster in new ceiling

nate — Thur, 27 Mar 2008 02:49:51 GMT

A ceiling I just had plastered had 17 cracks in it a few days after it was done. The walls had some too. My plasterer insists it was movement. There was a steel beam put in to replace the bearing wall in the middle of the room. He saids it's settling. There is no evidence of any movement o setlting at the two point loads and the beam was oversized and just as strong as the wall it replaced. Also the ceiling cracked in other areas that weren't affected by the beam and the walls cracked that were existing studs and had nowhere to shrk. He stated early on that his mixes has set up very quick and he was dry before he left (he said that was unusual) He now states that because I put a second layer of strapping perpendicular to the original layer that that was the problem.

Help me please.

nate

caulking before applying MOP?

cleta — Wed, 27 Feb 2008 17:42:23 GMT

Is this necessary? I was reading about this on a forum...someone doing VP and going back later to caulk between the wall and trim. I did not do this on my walls (didn't even know about it). The walls/trim are old and there are gaps between them in places, but I haven't had a difficult time getting a very clean line between the wall and trim...I just smoosh a little more MOP into any gap area. I figure that is one of the qualities of lime plaster, right? - i.e., that it is a great self-filler.

So - am I missing something? will there be problems down the road because I didn't caulk between the wall and trim? I looked through the MOP/VP instructions again and didn't see this mentioned in the prep steps. And I haven't heard of it being required with any other plaster, either.

sgrafito, impressed plaster

jesse — Wed, 27 Feb 2008 05:28:04 GMT

Anyone have experience with sgrafito, stencils, impressed designs, etc with venetian mop? We are trying to build up a portfolio of samples. Tips are appreciated.

new wood lathe / plaster construction

murray — Sat, 23 Feb 2008 00:18:11 GMT

Hello...I've been able to find lots of info on repairing or replacing old plaster but not much on new construction. I don't have road access to my place, and my building materials need to be moved by rowboat and hauled up a steep trail. Drywall is NOT going to be an option.

Cedar lathe is relatively affordable in my area. The cabin is rustic and I'm really not interested in mirror smooth finishes, a bit of texture would be just fine.

I'm interested in trying to do an old-style three coat plaster wall, but today everyone (like the structolite people) seems to insist on metal lathe for the products. Is this excessive caution? What would be a good product for a scratch coat and brown coat? Finish Coat? Or if anyone knows of any good resources on the internet for new plaster lathe construction that they could share??

Thanks so much,

murray

shower walls

Jesse — Tue, 12 Feb 2008 04:13:15 GMT

David and I are doing our first plaster shower walls. So far we have installed durock cement board and fib.glass taped the joints with a fill coat. Where the walls meet the tub we installed an aluminum angle iron with a drip edge cut into it. The angle iron is installed first, then the durock over it with a 1/2 inch reveal between the wall and the tub to allow proper breathing.

Mike, I noticed you mentioned in another thread to do a 1/8" thick coat of portland mixed with mop base, otherwise the joints will crack? We were planning on just applying 2 coats of base and 1 coat of finish as normal with some colors. If we should change our plans please let me know and provide any insight you have as to what the problem is and how the portland mix fixes it.

We have had many customers ask us about venetian plastered shower walls, and if this works we might have a nice new market niche.

Thanks,
Jesse

p.s. pics on our web site not before too long

Old master bedroom

Vincent — Tue, 12 Feb 2008 00:22:48 GMT

Hi,
I have a some questions about Restoration. I have A master Bedroom that I have to Fix, it has some cracks,and lead paint on the walls and ceiling,I will like to know, What can I do to support the ceiling that has cracks and it's loose.What would you recommend ?I heard plastic washers are good to support the walls , also for lime plaster should i prime first with oil / latex ? Can I use burlap or fiber mesh?

Thank you for your time,

Warm regards

Vincent,

rough coat under many layers of wallpaper

Loriann — Sat, 02 Feb 2008 21:25:32 GMT

I have an older home built in 1850, Southeastern Mass. I really would like to paint the bedroom, but after stripping 3 layers of wall paper I found rough coat horse hair plaster. The walls are in pretty good condition. There were some repairs but nothing bigger than 2" wide, and there are some quarter sized holes that need some filling.

I'm not overly handy, but not afraid to make an attempt. Would one of your products suit my need of creating a paintable surface???

Thanks for any info.
Loriann

"blistering" of finish coat

cleta — Thur, 31 Jan 2008 03:27:38 GMT

Am wondering what caused this and what to do about it. This did not happen on my test wall. Blisters or bubbles appear shortly after the finish coat is applied. For the most part, I could leave them alone and they would go away, but the bigger ones did not. A couple of them have turned into small cracks as they dry.

My thoughts are: finish coat too thick? I was applying slightly thicker on this wall as I have a very long arched edge of a barrel ceiling to cover. I wanted the edge to be nice and sturdy, so made the finish a little thicker there and on the wall leading to the edge so that there would be no weird transition. The problem seemed much less when I would go back to the super-thin layers.

too wet? i.e., this seemed to happen where I had sprayed over my edges to keep them wet - I had a couple of delays while doing this, so kept spraying - maybe too wet in areas?

I plan to apply a second finish coat - this is a very light color and I like the look of a second coat with this. So, I can knock these areas back, repair and then go on, I think. I did this on a couple of the larger spots already - just scraped off the finish that seemed to be lifting, smoothed the edges and re-troweled.

One other concern - because I figured out that I could go back and smooth these out with pressure on the trowel, I ended up smoothing and burnishing on this first coat more than I would like. Am I going to have trouble with the second coat sticking to a burnished surface?

Thanks!

plaster in shower?

tina therrien — Thur, 24 Jan 2008 14:57:52 GMT

hi there! i am a straw bale builder based out of Ontario, using some cement/lime finishes, and am starting to get into more traditional lime finishes. i am tiling a custom shower in my bathroom using dark slate tiles, and wonder about using lime plaster on one of the walls to create a brighter shower. the base is cement board...is it possible to use a lime plaster, and if so, what should it be protected with? if it is burnished sufficiently, will this offer much protection, or is there a wax/natural oil that can be used? to date, i've had mixed reviews about whether or not this would be a good idea.

many thanks for your assistance!

tina

Waxing

shayne — Mon, 21 Jan 2008 15:35:05 GMT

Hi MOP,

I'm over here in Burlington. Wondering what is the best way to seal MOP in kitchens or bathrooms? Wax? If so what kind and how?

Thanks,
Shayne

taping off over MOP finish coat

cleta — Mon, 14 Jan 2008 07:17:22 GMT

Hi Mike - I need to tape off over the finish coat to work in some striping with other colors of plaster. I will use the 3m orange core tape. How long do I need to wait after the finish coat is dry to do this? Is 48 hours long enough? I sure don't want to pull up any of that lovely finish!

thanks!

Cleta

Many Layers of Paint on Plaster Walls

Steven Breese — Sun, 06 Jan 2008 23:40:22 GMT

I am an experienced do-it-yourselfer, but have only assisted on one plaster job (a ceiling in a friend's house). I currently have a 100 year-old Victorian with an Entranceway/Hallway area that has been painted an re-painted/repaired many, many times. When I bought the house about 18 months ago, I was delighted how beautiful many of the plaster walls were - flat and smooth. Of course, the reason I am writing is, the Entranceway started peeling the minute I closed on the house and within a year 33% of the paint and repair material is peeling away in the Entranceway in huge pieces. I started scraping this weekend and now my once beautiful plaster walls are grossly irregular with various levels of paint and a few small holes. Normally, I would patch these areas with dry wall compound and paint a flat color and avoid side light. However, I have no idea why this paint came up and I dont want to be scraping and painting again next year. I want to assure you that I have found NO evidence of water/moisture and the paint peeled from both interior and exterior walls. I have scraped with various tools, but I do not see any way that I can get all the layers of paint off these wallswhat I mean is, I cannot get completely back down the original plaster. So here I am in Norfolk Virginia contemplating recovering these walls with thin dry wall, orhopefully...finding a way to rescue the plaster. In looking at your product, you obviously have a ton of experience with problems like mine. What do you think, can I save the plaster? Help me if you can. --Steven

Specialty Plaster LLC gets a website

Jesse — Fri, 04 Jan 2008 23:45:56 GMT

Specialty Plaster LLC, the NJ/PA distributor for mop just launched its website: http://www.specialtyplasterllc.com

the site is new and will probably undergo a lot of construction over the next few months

go master of plaster!

Jesse
jesse@specialtyplasterllc.com

Merry Christmas, Mike!

cleta — Mon, 24 Dec 2007 07:57:20 GMT

Hope you have wonderful holidays, Mike! All the best in the new year, too.

Cleta