stuff we forgot to post last year

last summer our front sunroom walls looked like this:

the wood between the windows was very rotten, so we decided we should rebuild that whole wall.  since we needed to accomplish this all in one day so the house wouldn’t be left open and vulnerable overnight, we enlisted the help of a few friends to brace up the roof and frame out the whole wall in one afternoon

here is is braced up with the windows removed:

since this room will be part of the house we will be making into our music studio, we decided to only put one large laminated window in the front wall.   laminated windows are better at sound isolation than regular run of the mill windows.  but they are also more expensive and a lot heavier.

here is the wall completed, before we installed the window:

the floor in this area of the house had many holes and was also very rotten, so we decided to take up the floor boards, add sisters to the floor joists that had sunken in too much, and put down a new subfloor.  we kept all of the salvageable  floor boards we could, by carefully using the flat bar on the groove side to lift it up and back so the tongue remains undamaged.  it doesn’t always work, but i’d say for every ten boards we tried to get up, probably one would get a little damaged.  then we took out the nails and piled them up to save for another project.

we finished our subfloor just in time to bring home a little puppy

walls and windows

we let the concrete set for a few days and then we started working on those block walls.  because the floor in there was previously a few feet higher than this on grade concrete slab, all of the window openings were way too high.   so our first step was to cut the window openings down lower.   we used a circular saw.

then we smashed out the blocks between the cuts with a sledge

then we framed out the window

we did this for the six windows openings and one door opening in this part of the house

then we put a layer of tyvek, and then a layer of that extra polyiso rigid foam board we have laying around.  that’s an r8.

then we framed out a wall in from of that, ran our electric wires, and put in roxul insulation between the studs.  that gives us r23 for these walls.  here are photos of this section from when we bought the house and now:

woods brother in law owns a window company and gave us this salvaged wooden door for our back entry.   we will eventually refinish it.   also in this picture you can see the passive solar working… the south facing windows are all letting the sun in and it’s hitting that concrete and heating it up.  if you put your hand on those sun spots, it will feel much warmer than the rest of the floor.  this will hopefully help add supplemental heat to this room, making this design more efficient.

hydronic radiant heat

we decided to go with a heat system called hydronic radiant, which can really be done many ways, but simply put you have hot water running through pipe under or in your floor.

the reasons for choosing this type of heating system:

- a forced air system blows warm air through a system of ductwork.  it also blows dust, pollen, etc. around and if you have allergies, this can make them worse.

- the radiant system heats the floor and objects in your room instead of the air, so you feel warm without having something blowing on you.  this also means you can set the thermostat much lower.  And the heat doesn’t rise as fast if it’s starting in the floor and the floor is holding that heat in.

- we are planning on turning half of our home into a music studio and we figured having ductwork would make sound isolation very difficult.   (in reality, it posed other problems that we didn’t think of… one of them being that we now can’t have a floating floor, which is the most effective way to ‘soundproof’ your floor)

so…

we decided to try a couple different methods.    half of our house still had a dirt floor, so with that section we decided to embed the pipe in concrete.  the other half of the house has wooden floor joist and subfloor, so for that section we ran the pex loops between the bays and stapled them up underneath the floor.

we got lots of information from  radiantdesigninstitute.com and ordered a layout from them.  the price was low for the amount of questions and support they gave us throughout the process.

for the section in concrete we did the following steps:

1. leveled out the dirt that was on the floor so we can get a good even start

2. figured out the height of the finished concrete by adding up the thickness of all of the layers of gravel, insulation, and concrete, then marked a line on the perimeter of the room by using a laser level (can also use transit)

3. put about an eight inch tall strip of 2″ rigid foam board touching the top of the perimeter line.  this is known as a bond break and it ensures that the heat from the concrete floor will not leach out from the sides through the exterior wall.   we also taped the seams with tyvek tape.  this bond break also served as a guide for where to pour the concrete up to.

4. shoveled in 4″ of gravel and tamped it down with a plate tamper.  this got the gravel nice and compact.

5. laid down a vapor barrier.  we bought a roll of 6 mil black, and the roll was large enough to do 2 layers, so we went ahead and added the second layer.  that way if the first layer gets any punctures from the gravel, the second layer should still do the job.

6.  then for the layer of insulation, we decided to also double it up.   earlier in the year, we got a large pile of polyiso boards from a contractor who over ordered.  they have a cardboard face to them, and are generally used for flat roof insulation.  we used that as our first layer of insulation, which we believe has an insulation value of R8.  then we bought 2″ thick boards of the blue dow rigid foam board (R10) for the final layer.  we taped the seams once they were laid down.

7.  then a layer of wire to reinforce the concrete

8. then it was time to lay out the loops of pex.  pex is now being used instead of copper pipe, which makes this type of heat system much more affordable and hopefully more likely to last longer without breaking.   we secured the pex to the wire with 8″ zip ties

9.  we hired a couple of guys to come in and pour the floor as well as some steps going down to the basement. we put a pressure test on the two loops of pex to make sure there weren’t any air leaks during the pour.

that’s pretty much it for that section.   we believe the concrete section will work better than the wooden section because mass stores heat very well, so when that concrete is heated up, it will stay warm on its own for a good amount of time.  also because our house is south facing, we put a big window on that side of the house and the sun will shine in, hit the concrete, and warm it up.  that’s called passive solar.  in the summer the sun will not hit the concrete floor because we have a good overhang and the summer sun is much much higher in the sky than the winter sun.

in all, we have 6 loops of the pex, and each loop is between 300 and 400 feet long.  500 feet is the maximum length of pipe you should use before the water in the pex loses too much heat.   we ran all of the pex in the system to the manifold, but for the soldering of copper, pumps, heat exchanger, and expansion tank from the manifold to the water heater, we had our plumber friend george help us.

for this system you can choose between tankless water heater, boiler, or water tank.  we went with a high efficiency water tank because the tankless weirds us out a little and the boiler is too powerful for the size of our house.  this water heater also heats all of our domestic water.