mass timber construction

It’s Been Grate

A lot has been happening here on the ground with the Breathing Wall Mass Timber Research Project team. The team said goodbye to Anna Halepaska a few weeks ago as she made her way to McGill University to pursue her PhD in architecture under Salmaan Craig, a main collaborator on this two-year research project. Huge congratulations to her and her future in research! 

Fergie and Preston are here at Rural Studio finishing up the construction of the breathing wall mass timber test buildings. The roof is nearly complete! The majority of the roof metal has been screwed down to the purlins and the two teammates are finishing up the south end this week. The south side acts as a hip roof for water drainage while the north side is an open, angled gable end. 

Last week the team (with the help of a few of our new 5th-years on campus!) poured concrete footings and set the posts for the metal grate walkway. Once the angles were welded to the post, the walkway was put in place. Borrowing a few details from the Perry Lakes projects, the stairs were welded in place to complete the full walkway. Next up, doors! 

Yet again, the team used an older Rural Studio project, Newbern Town Hall, as a precedent for the door detail. The steel angle frame is attached to the exterior wall only at the top while the side clips keep the door frame flush but are not fastened directly to the frame. Wood expands and contracts over time so this detail gives the door an opportunity to expand and contract with the wood, riding up and down the exterior wall along the clips. This also minimizes thermal bridging around the opening. Keep an eye out for the final door install! 

The to-do list is getting shorter by the day. The team will be installing the doors and running the electrical next week to wrap up the construction of both test buildings. Stay tuned for an update on the team’s research paper and the peer review process! 

Getting used to the heat,

The not-always-sweaty massive breathers 

Soundtrack: Closing Time | Semisonic 

Back in Business

The Mass Timber Breathing Wall Research team has been in quarantine for the past several months, but they’ve kept themselves busy. The summer was spent finishing up experiments, carefully documenting data, and finally writing and submitting a paper on their research to a scientific journal for peer review. The team is currently waiting to hear back from the journal, but keep an eye out for a future post with details!

Now that a new semester has begun, the team is back on site (following COVID-safe protocols!) and finishing up the two mass timber test buildings on Morrisette campus. After sitting under a tarp for a few months, the pods needed a little TLC. But one of the benefits of stacked timber construction using threaded rods is the ability to take the building apart again – which is great for test buildings that may need to be altered in the future. The team (plus our volunteer, honorary teammate, and Rural Studio graduate student, Charlie Firestone) unstacked, re-braced, and re-stacked the walls and ceilings for both pods over the course of two weeks.

Once all of the wood was up, steel plates and angles were threaded on along the ceiling and floor to evenly distribute force from the threaded rods. The walls were tightened down, and lag screws driven through the thinner North and South walls to pull the corners tight. A layer of sill seal (a compressible gasket) in all of the joints ensures that any gaps or irregularities are sealed. Finally, a couple coats of spar urethane sealant protects the pine from moisture and mildew.

Switching material palettes for the roof, a steel space-frame spans over and between the two timber ‘boxes’ to support the corrugated metal roof. The team fabricated all of their trusses last year in Birmingham (thanks again to Turnipseed International and the guys at the shop!), so they were ready to go up as soon as the wood was sealed. It was a long morning in the Hale County heat, but with the help of Prof. Steve Long and the Bobcat everything went up smoothly. Purlins were welded in place, and corrugated sheet metal will be going up soon!

Since the days get so hot here in the summer, afternoons have been spent doing prep work for the next day and finishing interior details. The lofts (which are centered over the space to prevent asymmetric airflow) were installed, resting on ledgers which run along the east and west structural walls. Railings and ladders – fabricated from 1” steel tubes – were screwed in place.

The last few tasks are installing the roof metal, doors, a metal grate walkway that runs along the front of the two buildings for access, and lighting and electrical. Stay tuned for updates on the paper, and finishing details on the two test buildings!

Constantly sweating,

The Master Builders

Soundtrack: We’re Still Here | For Giants

Zoom Roast

Unfortunately, due to COVID-19, Rural Studio had to cancel the Pig Roast celebration hosted at the end of each spring semester to acknowledge the work happening in Newbern. To conclude the team’s two years of research, the team presented to a wide range of reviewers in a “Zoom Roast.” This celebration/critical review allowed the team to share their work as well as receive feedback on how to continue moving forward. Thank you to the Rural Studio faculty, Auburn University faculty, and our project collaborators from McGill University and Auburn University for spending the morning reviewing the project on Zoom. Also a huge thank you to Michael Jemtrud from McGill University, Z Smith from Eskew Dumez Ripple, Billie Faircloth from Kieran TImberlake, and Jonathan Grinham from the GSD at Harvard University for coming in as guest reviewers to critique the research project.

Zoom Roast with reviews from Auburn University, Rural Studio, McGill University, Harvard University, New Orleans, and Philadelphia.
Overview of experiments the team conducted in their two year research project.

The team is currently working on a draft of their first peer reviewed paper (!!!) to be published in Energy and Buildings. The “zoom roast” was an opportunity to analyze the experimental set ups before beginning the peer review process. The team has been working closely with Salmaan Craig in the past few months to finalize a draft focusing on three experiments the team completed in the past year. The paper explores a method of integrating ventilation and heating into a mass timber envelope, allowing for a mono-material building that is able to sequester carbon and reduce greenhouse gases while also reducing the need for mechanical ventilation systems. The experiments in the paper lays out 1) how to optimize panel geometry and identify the design space for this system, 2) how the system could be synchronized with natural ventilation flows to obviate conventional HVAC, and 3) how transient behaviors affect the system. 

The team is also working on writing up the results and testing method for the thermal conductivity testing they completed in the engineering lab at Auburn University to be published in an architectural journal. 

The team tested a variety of pine samples measuring the thermal conductivity of each.

Stay tuned for links to both of these papers once published and available to the public! 

From Builders to Writers,

The Jubilant Journalists 

Soundtrack: Paperback Writer  |  The Beatles

Stacks on Stacks on Stacks

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. 

Back in our welding gear, 

The Metal Masses

Soundtrack: Woodstock | Portugal. The Man

Rain, Rain, Go Away

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. 

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. 

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! 

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