Thursday, January 23, 2014

Insulation

One item, unseen in the finished project that we took very seriously was air sealing and insulation. The deltec package comes with 1" foam (R5) over the entire exterior to act as a thermal break and foam gaskets at framing and sheathing intersections. The Deltec page probably explains and shows it best.

The house walls are staggered 2x4 studs, used to make a 10" thick final wall, so lots of room for insulation, garage walls are just 2x4.

We used 4"spray foam on all exterior walls and filled the remainder of the cavity with cellulose insulation. The spray foam makes an excellent air seal as it expands into any cracks. Then a light cloth membrane was stapled to the studs so the dense pack cellulose is contained.





There is a lot of scraping and using a really, really long sawzall blade to trim excess foam off.



Interior walls filled with dense pack to provide some soundproofing.



The last step was to do a blower door test, which pressurizes the whole house to see how much air leaks out and where. The house was tight enough that we didn't have much to track down, but I got to wander around with an IR camera and look for cold spots and a smoke pen to find any spots where air was being pulled into the house.




One of the really interesting things about the last photo is you can really see how cold the studs are (if you click to enlarge). This is the garage and is 2x4 construction, so we have a lot of thermal bridging bringing cold  in. This is one of the reasons a staggered stud 2x10 wall really makes sense as that technique goes a long way to eliminating thermal bridging.



Where Wood Comes from Part 2

In part one of this post we got to the point of rough boards. Those boards have to be finished so they can be used for trim and ceilings (our intended end use).

We had seven dried stacks of rough cut, each about 1,000 square feet, so a pretty big finishing project.




The first step is to cut off any cracked or twisted ends. Most boards (even though we sealed them) needed 4 or so inched cut off each end.

Rough lumber isn't exactly straight, so next we clamped the board to a straight edged sled to run it through the table saw to give us one pretty straight edge. We would do a bunch of boards then readjust the table saw and pass them back through the table saw to straighten the other edge.

The below photos show a board prior to the first pass and after with one edge straightened.


Next the boards were run over the jointer to make a flat bottom, that can take 2 or 3 or 4 or more passes depending on how warped or how many knots are sticking up.


We tried to run boards with the cupped side down through the jointer as we could leave some rough spots that were centered on the boards as only one side of the boards was going to be seen.Below is a piece done going through the planer, with a fairly rough bottom side.


The next process was planing, again taking several passes through a machine that shaves the top off the board, taking a bit off on each pass till we have a fairly smooth top at the point where the board thickness is the same for every board.

For the majority of the boards (those becoming ceiling) were then sent through the tablesaw one last time to make a groove so the boards could be butted together. We did not do tongue and grooves that interlock as that would have been overkill for our use.

The last machine step was a pass or two through a sander to smooth out any machining marks and raised grain and minor surface issues. Below shows an unfinished cutoff end on planed and jointed boards. It also shows the clear difference between basswood (lighter on left) and ash (much more pronounced grain - on right).




Then the boards were sealed with landarc finish.

Then cut to length and installed.


Backing all the mechanical processes up was a custom rigged dust collection system. With 7 +-12'x4'x6' pallets of rough cut wood, each in excess of 3000lbs and a good portion of that being turned into wood chips and sawdust a solid dust collection system was critical to the operation. I took a cheapo Grizzly bag style collector, coupled it with a cyclone bought off ebay, used 55 gallon plastic drums to collect dust, piped the exhaust air out the back wall to avoid any filters, made one central vac attachment point that quickly switches from machine to machine, and most importantly put it in the garage space so the noise is not in the shop.


All the machines take maintenance, adjusting based on amount of variance of each board, sharpening/blade changing, lubing, dusting, emptying big containers of dust.

I learned that to make a bunch of trees into a big pile of finished wood means a REALLY lot of handling of each piece, a lot of sawdust, a lot of scrap wood for kindling.

Wednesday, January 15, 2014

Framing!

Framing was generally fun and exciting as we could actually see how rooms would look and feel. It was a cold task for the carpenters as it happened before insulation (winter 2013, so a year ago). None of the interior walls are weight supporting, so they can go just about anywhere.