The team (finally) beat the rain for a few days and finished stacking the two test buildings. The construction process is extremely quick due to the threaded rod construction method. The team organized the wood on site then spent a few days stacking each piece of timber on the threaded rods.
Next step is the metal roof! For now, here are a few aesthetically pleasing mass timber photos for your feed.
The Breathing Wall Mass Timber Research Project team has been quickly jumping between testing scales as the research continues. The test cell, introduced in the last blog post, is now finished- fully covered in a rigid layer of Geofoam insulation and ready for testing! The team is currently working on a large scale thermally active surface design to get these tests running.
Thermally Active Surface (TAS) construction
TAS construction
Geofoam test cell completed
In the meantime, the team also built 1 of 2 test buildings. As a reminder, there will be two test buildings. One will be only mass timber construction and the other will couple mass timber construction with the Breathing Wall system. The team took advantage of every ounce of sunshine last week to build the mass timber test building in just under 3 days. Because of all the wood prep done before Christmas break and the threaded rod construction, all the team had to do was stack the 2x4s and 2x6s to form the walls.
mass timber testing building in progress
The ceiling was the real trick. Because the threaded rods for the walls run through the floor and the ceiling (tying the whole test building together), the team had to ensure the holes on the ceiling would line up perfectly with the vertical threaded rods. So the team built the ceiling off site, tightened it down to an exact measurement, drilled the holes, then took it apart. When the walls were up, the ceiling was installed in exactly the same order as it was assembled before to ensure the holes lines up with the threaded rods. Next up, doors!
mass timber ceiling made off site
mass timber test building
mass timber wall construction
ceiling construction with chimney opening
Stay tuned for another test building, doors, and a roof coming together very swiftly.
Praying for sunshine,
The Always Damp Breathers
Soundtrack: Have You Ever Seen the Rain? | Creedence Clearwater Revival
As construction continues, the team is also spending their spare time (ha!) scaling up in the horizontal and vertical sock tests. Each increase in scale comprises of another variable added to the test. This testing method isolates the effects of each variable. The horizontal sock test has moved up in scale to a new test box the team lovingly refers to as Zelda – you may recognize her from earlier air infiltration tests, where the team was experimenting with different laminated timber assemblies. Zelda adds the element of these laminated panels in a forced-air system in comparison to the previous solid wood panel. With the laminated panels, the team will also be testing different hole spacings for the Breathing Wall to try and find the most optimized geometry for the Test Buildings.
mass timber Breathing Wall panel
thermally active surface is applied to the interior face of the Breathing Wall
horizontal sock test set up using Zelda and a large scale Breathing Wall panel
Jumping even larger in scale, the team is constructing their test cell. This cell serves as a way to test a full-scale Breathing Wall in isolation. The cell is the same dimension as the future Breathing Wall Mass Timber test buildings, but the floor, ceiling, and three of the walls are standard stud-framing with hyper-insulation. The Breathing Wall is added to one side of the cell for testing. This eliminates the variable of the mass timber construction so the team can use this data to compare with their final test buildings. One of those buildings will test the whole Breathing Wall Mass Timber system, while the other will be only mass timber to serve as a control. Like the rest of their experiments, these steps should allow the team to understand the impact of each variable and strengthen their understanding of the whole system!
insulated test cell
mass timber Breathing Wall panel in the fully insulated test cell
Stay tuned for a fully insulated vertical sock and test buildings!
The research team has spent the past few weeks constantly shifting between testing and building which keeps things exciting around here. With the floors for the two test buildings in place, the team spent about three weeks preparing each piece of wood for the walls and ceiling. Over 700 pieces of wood were cut, labeled, drilled (4000+ holes), and stacked. For a while, the team operated each day under the fabrication pavilion like a well-oiled machine. Each team member had their job: book-matching boards, clamping templates, drilling holes, stacking finished pairs. By the end of those weeks, the team could prep an entire wall (~80 boards, 400 holes) in a little over a day!
4000+ hole drilled!
each piece is book matched for wall, ceiling, and floor construction
Upon returning to Newbern, the team continued the metal theme and spent the first day back coating all of the metal elements of the pod with a clear lacquer finish to prevent weathering while maintaining the unfinished look of the metal. Then they made the switch back to working with wood.
With all of the wood for the floors prepped and ready to go, installing the floors was a simple and quick process. Of course, before the wood could be placed, the world’s most substantial termite shields had to be installed. The termite shields comprise of ¼” steel plate welded into a box and are designed to complement the massiveness of the mass timber and concrete foundations.
After the termite shields were siliconed in place, the wood for the floors was placed, a process which took about fifteen minutes. Then the wood was roughly aligned so that the threaded rods could be inserted. Once the rods were in place and lighted fastened, the wood received its final alignment. By far the most time consuming part of this process was tightening the threaded rods as, even with our preliminary tightening, the wood still had subtle warping and cupping that needed to be squished out. The floor installation overall took about five hours, four of which went into tightening the threaded rods.
Stay tuned for the rest of the pod coming after Christmas.
Building is getting serious,
The Fabulous Floor Folk
Soundtrack: Construction Site Song | The Kiboomers
