Twelve batches into the second coat

The second coat (also called the brown or infill coat) of plaster takes a lot of mud. Of course, we already knew that based upon our plastering experiences two years ago when we finished the exterior of the house.

The recipe that I’ve been using for the second coat is different than the recipe for the first coat (also called scratch or discovery coat). The first coat has a fairly high clay content. I used 1.5 parts clay-rich dirt to 2 parts sand. It can be done with equal parts clay and sand (there are variations depending on the clay content of the dirt being used). The more clay there is in the mix, the more cracking that occurs when the plaster dries. This is because clay expands when wet and shrinks when it dries. So, as the plaster dries, it naturally shrinks, and the shrinkage causes cracks (something has to give somewhere). For the first coat, that’s not a big deal – the cracks will be filled by the next coat and will actually help the second key into the first.

For the second coat I started with a mix using 1 part clay to 2 parts sand, but I’ve adjusted that on the last four batches to 1 part clay to 2.5 parts sand. Although cracks on this coat of plaster aren’t a real problem because they will be covered by the finish coat, I would like to minimize them as much as is realistic.

I’ve noticed that cracks are more apt to appear in areas where the plaster is thicker on the wall, presumably because the thinner areas surrounding the thicker dry faster, shrinking as they do. The thicker areas take longer to dry and are still wet enough to be weaker and therefore the first place to give. Less clay in the mix will allow less shrinkage and fewer cracks. The important part is that the plaster be strong enough, a characteristic dependent to a large extent upon the clay which is the substance that binds the plaster together, that makes it work (sand and water doesn’t make a good plaster).

We’ve mixed 12 batches of plaster for the second coat so far. We started in the kitchen, because I want the walls there to dry so we can put up the green board. They are mostly dry now, with only a few areas still damp. The weather played a role in that – it was humid and overcast with rain for several days. That’s not good drying weather. But, drier weather has returned, allowing the process to continue as needed.

The kitchen windows were the first ones I did with the second coat. They went well. The greatest challenge is above the windows. Somehow, gravity seems to work against me, causing plaster to fall. Sometimes it’s because it sticks to my hands more strongly than it sticks to the first coat, I think. But, once it’s pressed in firmly and troweled, it does fine. It’s just initially that a fair bit falls to the window sill. I pick it up and use it anyway (it’s not like it’s going to get dirty).

After the plaster is troweled and shaped, the windows look good. The important thing is to get the shape on the walls with this coat. Around the windows that means the curves I want. On the rest of the walls, the kitchen walls excepted, the idea is to even them out and give them the shape and smoothness desired in the final product. There will be a few areas that will need a third coat, though – some of the low spots require 4 inches or so of plaster, and that is too much at one time in some areas.

After the kitchen, we moved along the wall into the dining room. This wall has the most area to be plastered of all the wall sections. It’s 14 feet long, 9 feet tall, and has only one window. We finished it yesterday and then moved on to the living room walls. As you can imagine looking at the photo (to the right – click to enlarge any of the photos), the areas above the braces on the timber frame present some challenges because of the limited space to work in.

The wall near the chimney behind where the wood stove will be located presented the challenge of plastering behind the chimney. It wasn’t too bad, and, thankfully, it will not be seen anyway. This section of wall will require a third coat in places because of the depth of some low spots.

We moved on from the chimney, around the front door and to the double windows in the living room. We didn’t finish the living room walls today, but we’ve got a good start. It should only take one more batch to finish the second wall. The front wall is done.

We mixed and applied three batches of finish coat on the interior packed walls in the master bedroom earlier in the week. Interestingly, the finish plaster that we put on the upstairs walls a few weeks ago did not dry white as expected. It is white in places, but not as uniformly as I anticipated, like it did when I did a test patch last year after buying the kaolin clay. The only difference I know of in the mix is the addition of wheat paste. I bought some dried wheat past to help bind the plaster together, and I think it is keeping some of the clay from working to the surface when I hard trowel and buff the plaster. That’s okay because we’re going to paint all the walls with a clay paint anyway. The wheat paste does a good job binding the plaster, though, and it keeps the clay from dusting off if you rub on it. It makes a nice finished surface.

It looks like the walls in the bedroom may dry mottled in color, too. There are a few cracks that have developed as the plaster is drying. I’m going to adjust the amount of clay in the recipe. My books recommended more clay in the final coat than I expected, and I went with their recommendation. I think less clay will still work fine and will allow fewer cracks. I need to get some silica sand so that I can mix up some plaster with it to repair the cracks. Masonry sand, even when screened through a window screen, has too many large pieces to make a good patch plaster. I’m going to want some fine silica sand for the clay paint anyway.

In the next few weeks, I’m going to experiment with the clay paint, mixing up different batches to find a recipe that I like. It should be fun trying it out with additives like mica powder and/or mica flakes. I also have some natural yellow ochre pigment to see if I can come up with a nice pale yellow.

Roof leak fixed (I hope)

We had 3 inches of rain early this week, and it was apparent that there was still a leak in the roof in spite of the new flashing I installed. The flashing didn’t solve the problem because the issue it is intended to address obviously wasn’t the cause of the leak as I thought. The location from which the water was entering the house and getting into the straw narrowed down the source to somewhere near the chimney.

Once the rain quit, I investigated. The flashing around the chimney looked good except for one place – along the seam in one section on a rib of the metal roofing. All of the polyurethane caulk I used was well sealed to the roof and there were no other apparent entry points for water. That one point would be all that it took. It didn’t allow a lot of water to get in, just enough to cause problems, greater problems later on if not dealt with.

The photo at the right was taken in October of last year after I finished the chimney. It shows the flashing I installed. The suspected entry-point for the water is along the left edge of the flashing. the edge of it actually comes upon on one of the metal ribs. There was a place along there that looked as if water could get past the defensive measures I put into place.

I had been intending to dress things up around the chimney anyway. The leak provided motivation to get it done now. My fix involved roofing tar, silicone caulk, and a sheet of roofing metal. First (sorry, no photos of in-process), I tarred the upper seam of the flashing and the outer edges on the right and left. I cut a piece of roofing metal to fit around the chimney, open on the lower side. I removed screws from the roof above the chimney and then inserted the new piece of metal under the seam of the upper row of metal above the chimney and around the chimney. I wanted to leave it as one complete piece, but I had to cut off one side to get it around the chimney. This wasn’t a problem because they were plenty of overlap. I sealed all seams with silicone. Then, I screwed the new piece of metal securely to the roof.

Now, water will have to find a way past the caulked seams of the new sheet of metal and past the tarred edges of the flashing (now securely tarred to the underside of the new metal). I added some extra roofing tar around the back and sides on the outside where the metal comes against the chimney. It looks better and should keep out water when it rains. Now, we’ll wait until it rains again to see if I’ve solved the problem.

First smoke–building the chimney part 2

After getting started on the chimney nearly a month ago, I continued to work on it as the weather permitted and as I had time. The first day on my own, I was able to install the thimble where the stove pipe will connect on the inside, and I was able to continue above it a few courses. The next day required cutting a hole in the roof and extending the chimney above the house.

I was able to take the chimney high enough above the roof that day so that I could flash around it, just in case it decided to rain. For flashing, I used aluminum flashing material that I already had. I put a piece across the front, pieces up each side, and a piece across the back of the chimney. Also, when laying the bricks, I etched the mortar for step flashing on the sides and for the flashing on the back. Based upon a recommendation, I used polyurethane caulk to seal the edges of the flashing and underneath it.

As the chimney continued to build high, it became necessary to set up scaffolding in order to keep it going. I nailed some 2x8s together, leveled up this framework on the roof in front of the chimney, tied it to the portion of the chimney already constructed so that it couldn’t slip out of place, and set up a section of scaffolding on top. This worked out very well. I was able to build the chimney nine feet above the roof with this one section of scaffolding.

I debated making the chimney only 7 feet above the roof, but finally decided on going the full 9 feet. I figured it would be easier to add the extra section of liner and bricks now than it would be to do it later on if it became necessary.

Finally, on October 11, I finished the chimney. It is 20 feet tall, extending from first floor level in the house (it stands on its own foundation). On that day, I laid 14 courses of brick and capped it with mortar around the last few inches of the clay liner. I took down the scaffolding, finished the little bit of flashing that I hadn’t completed (some step flashing on the east side), added a little more polyurethane caulk, and took some photos.

 

 

 

 

 

 

 

 

 

 

At the end of last week, Dad and Danny helped me get the wood stove I’ve had in the garage for the last several years (it’s one we heated our current home with for a couple of winters after we first moved here) into my truck and on the porch of the new house. Today, Ramiah cleaned the stove. So, this afternoon, I took it in the house and connected it to the chimney.

With the stove hooked up, I decided to build a small fire to inaugurate the chimney. So, this evening, we had first smoke in the new chimney. It was exciting!

Building the chimney (part 1)

Yesterday, a good friend came over to help me begin building the chimney for the house. Previously, I poured a footer and built a block foundation for it, but I hadn’t started on the actual chimney yet. Although I’ve read a little about how to lay brick, I wasn’t quite sure about tackling the project by myself. So, I asked David if he would help since he has laid brick on many different jobs in the past. He was glad to assist.

David showed me the basic technique, which for this job is not too difficult. I’ve laid a few concrete blocks with mortar in the past, and this brick work was easier, as far as I’m concerned. The biggest concern is keeping things level and plumb as it goes up. We used levels to check things on each course. My biggest concern is going straight up to the hole I have cut in the ceiling through which the chimney is supposed to go. We seem to be on line for that.

We put a clean out access door near the floor. I’m not sure how the door I bought for this purpose was intended to be attached, but we figured out how to get the job done.

The thimble for the stove pipe coming from the stove will be just above the narrow window which is on the wall that will be behind the stove. By the time we finished yesterday, we were at that level which is about seven feet off of the floor, having set the flue liner with the hole for the thimble.

I’ll finish the chimney during the next couple of weeks, depending on the weather. It’s been kind of wet here for a few days which isn’t good for laying brick outside. I’ll need to push it through the roof next, so I will be working on the outside. It’ll be interesting laying the bricks as the chimney goes through the ceiling and roof area, but I’ll manage.

I’m happy with how it’s looking. I bought these bricks mainly because the brick place was selling them at clearance price, trying to sell their remaining stock. I ended up buying them for less than 15 cents apiece (less than half price). However, seeing them as they become a chimney, I like how they look really well. It’s going to be a nice looking chimney.