The 57 acres that comprise Cedar Ridge Farm are located in the beautiful rolling hills of South Central Kentucky. My wife, our four children, and I are on a homesteading adventure as we work toward increased self-sufficiency. We grow much of our own food and enjoy being in touch with the agrarian roots of our lives.

One of the major projects we have undertaken is the building of our own home. The house we're building has three major distinguishing features: 1. we're building it without incurring any debt; 2. it is a timber frame structure; and 3. the exterior walls will be plastered straw bales. We live debt and mortgage free, and building our house with that approach makes perfect sense. Large timbers in a home possess a beauty and project a sense of strength, stability, and warmth that we want in our home. Straw bale walls provide insulation and make ecological sense. This blog is a record of our home-building project.

Monday, October 24, 2011

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. 003Based 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.009 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!


Wednesday, September 21, 2011

Building the chimney (part 1)

013Yesterday, 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 003blocks 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. 014By 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,028 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.

More slip straw

As I’m able, I continue to work on the house. There are many different projects to keep me busy, of course. As things come together, even though there is a lot yet to do, I am beginning to see the light at the end of the tunnel. We will get it done and be able to move in sometime.

On the first day this week, three families came over to help pack straw in some of the interior walls. We really appreciate their willingness to help. We all enjoy spending time together.

There are still several walls to be packed before they’re all done, but we made some good progress. We packed the wall behind the stairs, the wall on the kitchen side of the pantry, part of one wall in the hallway, and half of another wall in Robert’s room.

One of the most time consuming aspects of slip straw is moving the forms, but there’s no way around that. It’s actually a fairly simple process, and it makes a nice product.


Saturday, September 3, 2011


As I took lumber that’s been stacked in the barn for the last five years to have it milled into flooring and began to see how much (or little) I actually had, I began to think about one of my plans. I’ve been planning on putting up a wood ceiling in the kitchen, mudroom, laundry room, and Robert’s room (the room that was going to be the sewing room/study but which we redesigned to be a guest room – Robert is a friend for whom it is currently intended). But, as I saw my supply of wood diminish, and knowing that I have need for more dry 036boards for base board, moldings, cabinets, doors, etc., I felt a need to explore other options.

I finally decided to put up drywall ceilings in these areas. I will paint them with the same clay paint that I will make for the other walls. 042It should make these areas brighter than they would’ve been otherwise, and it preserves my other wood pile near the garage for some of the other needs I anticipate.

So, earlier this week, I brought home enough drywall for the ceilings that needed done. I also bought some moisture resistant green board drywall and insulation for completing the 040root cellar.

I spent time this week putting up ceilings and was able to get them all up by yesterday afternoon. I also had time to begin taping and mudding seams in the kitchen before it was time to quit yesterday. As I like to have it happen, the only waste from the sheets of drywall I bought were small pieces and one piece about 3 feet by 4 feet.

Getting muddy again: plaster and slip straw

There are many different projects to work on in the house. I have the luxury of focusing on just one thing or working on several at any particular time. Sometimes, diversity is nice. It’s also nice to get a particular project or focus completed.

When I got the bags of clay for the finish plaster moved into the house, I mixed up a small batch to put on a wall in order to see how it will look. Because it is powdered clay, it feels very different from the material we’ve been working with that we dug out of the ground. It’s fluffy. I mixed the small batch in a bucket and applied it with a trowel on the living room wall which I had previously plastered (the slip straw wall).

I screened the sand through a window screen to remove the larger grains/small rocks. 014I mixed it at roughly two parts sand to one part clay. When wet, the plaster is gray in color. As it started to dry, I buffed it with a plastic lid cut out of a yogurt container. This helps to push the grains of sand into the plaster and make it smoother.

It turned out well. Once it dried, it was no longer gray but, rather, white, like it was supposed to be. It was a thin layer of plaster, and I didn’t get it all applied as evenly as I would like. There are areas with a different texture because I wet the trowel to try to help spread it a little more in places. These areas have a different feel and look than the other areas. That’s okay. This was a test patch to learn from. I’m thinking I’ll make an alis (a clay paint) to go over all of the walls when done. The alis will have wheat/flour paste as one of the ingredients to help 006give it a non-dusting texture. It doesn’t dust badly without it, but you can rub of clay if you try.

Last week, I felt like playing in the mud some more. So, I mixed and applied three batches of plaster to the bales on the front wall of the house, from where I left off on the wall that will be behind the wood stove to the corner of the living room. This coat uses a high clay content plaster and has to be worked into the bales. It’s applied by hand and actually feels good. It was neat to work the plaster around the curves near and above the windows and begin to see the look of plastered straw bale walls in the house.

002004You can see the plastering job in these photos. When they were taken, the plaster wasn’t completely dry yet. That’s why there are dark areas. I’m looking forward to applying the second coat which will begin to smooth out the walls and fill in the depressions and irregularities that are evident with the first coat. One of the things I did before I started to plaster was to nail a 1x2.5 inch board at the base of the wall. The plaster will come out flush with the board near the floor. 008Then, once the finished floor is installed, I will have a surface to nail base board to.

Earlier this week, the boys and I packed some slip straw in the girls room which is upstairs on the east end of the house. Earlier this summer, we had packed most of the walls in this room, but there were a few places that we didn’t get done and hadn’t finished yet. One of the things I’ve learned about slip straw is that the thicker the clay slip mixture, the stronger the wall. Previously, we’ve used some slip that would’ve made better walls if it had been thicker (more clay in it). They are all okay, I think, but the areas we packed using more 028clay in the slip are more dense and tight. I think I ought to do a video on slip straw…

We packed the closet walls which are on either side of the window on the north side of the room. I’ve imagined this window having a dormer-like feel because of how the walls will be, and it does. The closets also seem quite nice. They’re about 3.5 feet wide, and each upstairs bedroom will have two.

046While I was working on another project later in the week, Ramiah decided to pack some on the storage room wall on the east side upstairs above the living room. He mixed the slip and straw, put the forms on, packed, and moved the forms all on his own. I think he did a great job and am very proud of him.

Material accumulation

One of the things I’ve been doing recently is accumulating material for tasks to be completed on the house. Earlier this spring, I hauled some boards to a friend for him to plane them and tongue-and-groove them. These boards will become the finished floor in the house. A couple of weeks ago 015I took the rest of the boards to him and picked up the first half which he had gotten done. They’re now stacked inside the house awaiting the time when we’ll be ready to put them down. I’m sure I’ll have to move them a time or two as dictated by other jobs in the house before we actually begin installing the floor.

The flooring is oak and beech. The beech has a lot of character, including some spalting, in it. The oak overall is nice. The second set of boards to be done appeared to be of better quality than the first set. I also purchased about 300 square feet of maple flooring from a family that had some left over when they had new floor installed in their house. You can see the stacks of flooring in the photo to the left. The oak is in the living room and the other is in the kitchen/dining area.

Another item now residing inside the house is 20 bags of number 6 tile kaolin clay to be used for the finished plaster on the interior walls. You can see some of the bags stacked near the flooring in the kitchen/dining area in the photo above. I wasn’t sure how much I would actually need, so I ordered 2,000 pounds of it. I figured it was better to have too much than too little. I ordered the clay from Kentucky Mudworks which is located in Lexington. They have a special deal for in-state shipping. I met the truck in town to get the pallet loaded with the 20 50 pound bags of clay.

Several weeks ago I also bought bricks, mortar, and clay liner for building the chimney. I have yet to construct the chimney, though. The brick and flue liner are still on the trailer which is parked near the house. The bags of mortar are stored on the porch where they will not get wet.

I also have paint for painting the house. I needed to get some for painting the fascia boards before gutters are installed. So, I purchased enough to paint the whole house when we can.


(Examples of the flooring: beech in left photo, oak in right.)

Tanks for the water: part two


Although the cisterns are not collecting rain water, they are mostly ready to do so. We don’t have gutters on the house, yet – I’m waiting on the installers. Based on the bid I received for seamless gutters, it’s actually cheaper for me to let them install them than to buy and put up gutters myself. So, as soon as they schedule their crew to come do the job, we’ll have the house guttered. In the photo, you can see that I painted the fascia. This is the color that the whole house will be painted eventually.

I’ll detail later the construction of roof washers and screen filter that I’ll construct. The roof washers will divert the first several gallons of water coming off of the roof whenever it rains. The intention is to let the first bit of rain wash dirt and debris off of the roof so that it won’t end up in the cistern. The water will run through a screen before entering the cistern in order to keep leaves and things that get past the roof washers from being in the harvested water. The water should be clean enough for general household use, bathing, washing dishes, and laundry. All cooking and drinking water will be run through a ceramic filter first.

After we had the three tanks set in place, I rented a drill with a 3” concrete bore bit. With my dad’s help, I drilled a hole about two and half inches off of the bottom of each tank. The septic tanks are only set up with inlets and outlets near the top of the end walls. With the holes lower, I was able to connect the tanks to one another so that they will fill and empty as one tank rather than three individual tanks.

The three inch hole was a little over 1/2 inch larger than the exterior diameter of 2 inch PVC. So, I used some 1/4 inch Plexiglas and silicone caulk to seal these outlets. I used an 8 inch piece of 2 inch PVC (actually electrical conduit, but it’s the same thing as used for water, only a different color) threaded on both ends. The threaded fittings on each end tightened against the Plexiglas and sealed the holes around the pipe.

When I plumbed the tanks together, I put in ball valves on each tank so that I can isolate each tank separately for cleaning whenever deemed necessary in the future. I also plumbed in a drain line. I put all of these valves next to one another so that I will be able to access them easily. The tanks are in the hillside in front of the house, and there will be dirt completely covering them. On the down hill side, I will terrace the slope with beds for flowers or whatever so that it won’t be too steep. In one of the terraces I will have an access to the valves, about 36” deep inside a plastic barrel I cut the ends out of for this purpose.

I took the two inch line from the tank outlets and ran it into the crawl space of the house. I also teed off of it for a 3/4 inch line which I also ran into the house. The 3/4 inch line will supply the water to the pressure pump and the 2 inch line will be for installing a pitcher pump in the house and to provide the opportunity for additional pitcher pumps later on if necessary.

Since I was concerned that if we received a heavy rain during which water might flow into the cisterns faster than the 2 inch line connecting them together could keep up with (leading the first tank to reach full and need to overflow before the other two tanks), I connected the tanks together with 4 inch pipes at the level of the inlets on the side near the house. This ties the tanks together at that level and then serves as the overflow which will be run to the pond.

I used my loader tractor to push dirt around and onto the cisterns once I had them plumbed together. I still have to manually move some of the dirt since I don’t want to take the tractor on top of the tanks. In order to get them covered properly, I’m going to need some more dirt, which I have on the east side of the house. I’ll have to relocate a few things that are in the way before I can begin to move that dirt in order to finalize the landscaping around the cistern and generally in front of the house.

After more research, I decided not to put a coating on the inside of the tanks. It could potentially lead to more problems than plain concrete would. I cleaned the interior walls as well as I could, and I think they’re ready for water.

Friday, August 5, 2011

Tanks for the water

A couple of years ago, I started constructing a ferro-cement tank for water storage in the shed/garage near our current home. I planned the tank to hold about 5,000 gallons, collecting water off of the roof of the building. The idea was to run a water line down the hill to the new house from this cistern. The drop in elevation between the cistern and the house would provide about 25 pounds of water pressure. We also wanted to have a cistern for collecting water off of the roof of the new house at some point.

The ferro-cement tank is only partially constructed, and time to devote to its construction hasn’t been readily available. In order to facilitate an earlier move into the new house, we decided to go ahead and put in a cistern near it. I considered options for water storage, including buying a poly tank (or more than one), building a ferro-cement tank, etc. We finally decided that buying some concrete septic tanks would not be much more expensive than building a ferr0-cement tank and about half the price of a poly tank or any other commonly available water storage tank. It also would involve a lot less time than building a cistern.

I hired a guy to dig into the hill in front of the house to create a place to set three 1,500 gallon septic tanks. 001We decided on three of them in order to have enough capacity to survive without rain for two to three months. July and August have been fairly dry months since we’ve lived here. So, it seemed like a good idea to plan for enough water storage capacity to not run out during dry months.

This week, after getting the insulation taken care of, I leveled out the bottom of the excavation site in order to get it ready for the tanks. I hauled in 6 tons of rock to put in the bottom for the tanks to sit on. The intention is for them to have a solid base that won’t settle and cause any of them to crack and end up leaking.

After getting the site prepared on the fourth day of the week, I called to schedule delivery of the tanks yesterday morning. We got all three tanks set in place yesterday (and then baled the second cutting of hay).

Setting the first tank


The first one in place


And then there were two. . .


All three tanks in place

The plan now is to drill a 2” hole near the bottom of each tank in order to plumb them all together with shut-off valves for each tank. Also, the water line from the tanks into the house will come from this location. I’ll use one of the existing outlets for an overflow when the tanks are full. I’ll also construct some type of filtration system for the incoming water, which will be harvested off of the roof.

One other task I’d like to complete with the tanks is to coat the inside of them to ensure they won’t leak (they aren’t supposed to, anyway) and to prevent the water from taking on the smell and taste of concrete. I’ll be completing these tasks along with many others during the next couple of weeks.

Wednesday, August 3, 2011

“Well, it’s about time!” An update…

It seems like it’s been a long time since I’ve posted to my blog. Probably, because it has been a long time – over 2 months. I’ve not been doing nothing, just not blogging.

I’ve had a lot of different things vying for my time, as is usual for the summer months. Last year I put off a lot of things and worked on the house full time, but I’ve not been able to do that this year. So, I’ve not gotten as much done as I would like.

In this post I’ll try to provide an update on some of the things I have done since the last time I posted (was it really in May?).

We haven’t gotten any more interior walls packed with slip straw. I’d say we have about 65% of them left to do. All of the downstairs windows, 019except the bathroom windows, are bull-nosed now. I have to build the window sills/seats for the kitchen windows and the laundry room windows (and the bathroom windows). 015Then, the five upstairs windows need to be bull-nosed and the window sills installed. I was able to round the bale edges around the front door and on one side of the back door. 018

After purchasing materials to build a masonry chimney, I poured a footer for it. Then, I used concrete blocks to bring the base up to the level of the floor where I’ll be building the chimney. A friend will come over to help me with laying the brick for this project. He’s working on a job that will keep him busy for another week or two, which is fine because I haven’t gotten to the point of being ready to build the chimney yet anyway.

I did begin to plaster the wall behind the location of the chimney. I figured it would be easier to get the plastering done before the chimney is there in the way. 041I’ve only got the first coat on art of the wall so far. I attached some drywall at the top of the bales along this wall (the front wall) to close up a gap between the top course of bales and the beam running across the top of the wall. There was no way to effectively stuff it with straw. I’ll plaster over the drywall pieces later. 038So, they will disappear.

Once I got my hands in the mud, I had to plaster more than just this section of wall. So, I put the first coat of plaster on the slip straw wall in the living room. This wall is between the living room and the master bedroom. After I get the finish coat clay (which I ordered today), I’ll try a batch on this wall to see if it will be enough to finish it, or if I need to put another thin layer on the first coat before the finish coat.

Last week I went ahead and made arrangements for getting two more important jobs done. One of those is installing the cistern, and the other one is having the insulation blown in. I hired a local individual to come dig out the area where we are going to set three 1,500 gallon septic tanks for our cistern. I’ll plumb them together as one tank, and we’ll harvest rain water off of the roof to fill them. I also hope to develop a spring later on for filling the cistern. 046It didn’t take too long to dig into the hill in front of the house where the tanks will be set. I’ll post more on this process later.

Originally, for the insulation above the cathedral ceiling in the house, a friend of mine was going to bring his machine and dense pack cellulose. I took longer than expected in getting things ready for the insulation, and in the meantime he sold his machine. So, I hired an insulation contractor to insulate my roof. They blew in fiberglass in the space I constructed. They also insulated the kitchen, mud room,  laundry room, and guest room (used to be sewing/study) roofs. 042It actually didn’t cost much more than I expected to pay for having my friend do the job.

In preparation for the insulation, I had a few tasks to complete. I blocked in along the front outside wall where there were some gaps into the insulation space. I also blocked in some gaps on the back. I cut the chimney opening in the ceiling and framed it in (I figured it would be easier to do that now than after the insulation was blown in). I also stuffed straw above the kitchen and laundry room windows 052which I hadn’t done previously. I also stuffed straw above the top course of bales to bring the walls up to the ceiling level.

On the day scheduled for the job, yesterday, I removed some metal from the back of the house and cut holes in the sheeting to allow access for blowing in the insulation. It worked great. After they were done, I closed the holes back up and put the metal back on.

Inside, they stapled netting on the ceiling across the rafters and blew the insulation inside that. 048The R-values are 39 for the main ceiling and 28 for the other areas. I think they will effectively be a little higher than that.

There are a lot of things yet to be done before we will move in. One thing I’ve learned through building this house is that my plans and timetables don’t always work out as I imagine they will. I’m okay with that.

Thursday, May 26, 2011

Slip straw in more interior walls

We had some friends over on the first day of the week for a straw stuffing party. The previous week I bought two sheets of 3/4” plywood for another two sets of forms. I also mixed up about 60 gallons of clay slip in preparation.

We started on the wall between the living room and master bedroom next to the two sections the boys and I did earlier. We also worked on the wall beneath the stairway, the other interior wall in the master bedroom, and a couple of bathroom walls. By the end of the day, we’d completed most of the walls that we’d started.

On the next day, the boys and I were able to finish all of the walls that we’d started during the work party. Then on Tuesday afternoon, our whole family worked on one wall upstairs. Then, yesterday afternoon, we worked on another wall upstairs. We ought to be able to complete the rest of the walls in that bedroom and storage area (on the east end of the house) in another afternoon’s worth of work. I’ll share photos of our progress upstairs later.


Thursday, May 5, 2011

Window sills and curving bale corners

I’ve considered different options for the window sills in the house. One of the earlier ideas was to set stones in concrete – done right, this makes a very nice window sill/seat. Later, I decided to make them with wood, and I’ve been pondering upon how to build them.

On the first day of this week, I planed some poplar boards with the intention of using them for the window sills. Dad and I tried out the tongue and groove router bits I recently purchased on a couple of the boards. My idea was to put in a framework using 2x2s that the poplar boards would be nailed in to. As we routed out a couple tongues and grooves, I continued thinking about my method. As a result, I changed my plan for what to do.

I decided to use some 3/4” plywood as a sort of sub-sill and install finished boards later, probably using the same material as what I will use on the floor in the house. The plywood will give me a solid foundation to nail the finish boards to, and it actually will install more easily than the previous method I had in mind.

Wanting to try it out, I decided to start in the master bedroom. The first task was to shape the corners of the bales on the sides and above the window. I used my electric chain saw to knock off the corner of the bales on both sides and to cut 3/4” out 050of the top of the bales below the window (to set the plywood at the right height).

Once I had the sides curved and the bales above shaped (I describe the basic process below), I cut plywood to install for the sill. I attached it below the window to some thin strips of wood I nailed to the framing below the window, setting the top of the plywood even with the top of the 2x4 at the bottom of the window. The finished boards will will butt up against the window on top of the 2x4 framing the bottom of the window opening. I also set some 2x2s flush with the exterior surface of the bales below the sill to provide extra support. 006It turned out well. The photo of the window also shows one end of the opening for the sliding glass door which I also shaped.

Today, I worked on the living room windows. Looking into the corner, you can see how they looked before I started. Although we tried to stack them straight, he ends of the bales were uneven. It’s quite easy to remove straw from the ends of the bales in order to make them more even.

The first step in shaping the bales around the windows was to cut the corners off. My electric chainsaw worked well for this. 013I found that it wasn’t necessary to try to round the corners.

The next step was to cut a length of poultry netting/chicken wire to fit the height of the window. I stapled one edge into the 2x4 framing on the side of the window. Then, I stuffed straw into the gaps between bales and added straw where the 014bale ends needed built out a bit. The chicken wire serves to hold the straw against the bales and to form the desired curve.

I pulled the chicken wire around the curve and anchored it to the bale wall with a short stick behind one of the hard wood sapling pins in the wall. I worked from bottom to top, pulling the wire tight, anchoring it, 016stuffing straw where needed, pulling the wire tight, adding another anchor, etc. 017When I reached the top, the corner was rounded, and the wire was tight.

The final step was to staple the wire securely to the pin in the wall. With it stapled, I removed the anchor sticks and was ready for the other side.

When we stacked the bales, we laid a 2x6 across the window opening and secured it to the framework above so it wouldn’t sag. Then, the next course of bales was added on top of the 2x6. I needed to not only curve this edge above the windows, but I also needed to provide a 019surface for the plaster to adhere to later.

Again, I knocked the corner of the bales off with the chainsaw and then attached chicken wire to the top 2x4 of the window framing. I put loose straw on the wire and stuffed it into some voids. Then, I pulled it up tight to the bales above the window, pounding it into the curve in order to shape it how I wanted it. A 2x4 of the bale shelf is exposed one bale course above the window, and I stapled the wire to this. I completed this process in sections across the window.

With both of the double sets of windows in the living room shaped, it was time to install the plywood for the window sill. While I was cutting off the corners earlier, I also cut the height of the bales below the window a little. The first step in doing that was to cut the strings of the bales (to keep the strings from getting tangled in the saw). Since the bales were already securely in the wall, 031they weren’t going to go anywhere or fall apart with their strings cut.

I nailed a strip under the windows to attach that edge to and then laid the pieces of plywood I cut in place. With them nailed under the window, I attached some vertical pieces flush with the bale surface under the plywood. I used some pieces of oak that was close to 2”x2” which I had.

The plywood extends past the inside plane of the bales because I want the plaster to come up under it rather than in front of it. The plaster will actually help provide additional support for the sill. It should be solid since it’s attached front and back and rests on top of the straw bales.