mass timber

The Final Countdown

September 25, 2020

Exciting news from Hale County: the Breathing Wall Mass Timber Research Project (BWMT) test building construction is complete! Last week Fergie and Preston finalized the construction of two mass timber test buildings on Rural Studio’s campus. These test buildings will be used in the future for research on the breathing wall, thermal mass, and mass timber. The team is also in the peer review process for their scientific paper on their small-scale experiments. It’s been a busy two years!

As a quick update, these two mass timber buildings are the result of two years of design and experimentation on mass timber systems and their potential integration with breathing wall technology. The floors, walls, and ceilings are all dry-stacked timber compressed with threaded rods to ensure an air-tight envelope. All of the steel components were designed and fabricated to facilitate the BWMT experiment: a steel roof acts an umbrella to protect against solar radiation and wind-driven rain; doors are hung from the top on the exterior to adjust to expanding timber; and steel plates and angles spread pressure from the threaded rods evenly through the timber. On the interior, flexible loft spaces are accompanied by fabricated railings and ladders, with a simple conduit carrying all electrical and lighting. The entire project was designed with flexibility in mind, so they can be used for future experimentation. The goal isn’t that these buildings are precious, but that they’re useful.

The past two years have definitely been a learning experience – doing scientific research at an architecture school was difficult at times, but the tension between the two really propelled the team and the project. The team learned to leverage the scientific aspect to inform their architectural decisions and to use their architectural knowledge to keep the research grounded. In the end, the design was stronger because it was backed by actual research; science and architecture can and should go together.

The team would like to thank the many reviewers and supporters who helped further this project for the past two years. Thank you to the Rural Studio faculty and staff, particularly Andrew Freear and Steve Long. Thank you to all who donated gifts, materials, and time. Thank you to the team’s studiomates, friends, and family for the constant support. Thank you to the Newbern community for welcoming the team in and taking them under their wings. And huge thank you to Salmaan Craig and Kiel Moe at McGill University and David Kennedy at Auburn University who volunteered their time each week to invest in and further this research.

Rural Studio is a place filled with magic and the team was extremely thankful to have been a small part of it for the past two years. The team served not only as students but community members, scientists, buildings, chefs, and farmers (to name a few.) They gained an understanding of the importance of being a part of the place and the community. All four team members are committed to taking what was learned in and out of the classroom forward with them as they move on from Hale County.

As for the team, Jake has been in New Orleans researching mass timber as a Research Fellow for Eskew+Dumez+Ripple. Anna is pursuing her PhD at McGill University furthering the study of the Breathing Wall. Fergie and Preston are moving to the mountains of Colorado to chase some design-build dreams. The team looks forward to the many visits back to Hale County and Rural Studio. That’s a wrap!

Not leaving Hale forever,

The Mass Breathers

Soundtrack: The Final Countdown | Europe

Tags: breathing wall, mass timber, Mass Timber Breathing Wall Research Project, mass timber construction, research project, timber research

It’s Been Grate

September 9, 2020

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

Tags: breathing wall, mass timber, Mass Timber Breathing Wall Research Project, mass timber construction, research project, timber research

Back in Business

August 17, 2020

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

Tags: breathing wall, mass timber, Mass Timber Breathing Wall Research Project, mass timber construction, natural ventilation, research paper, research project

Wood you believe we did it?

June 15, 2020

Timber pun prepared and deployed? Scientific apparatus built? Yes to both! Live from HomeLab, the Thermal Mass and Buoyancy Ventilation Research Project team is proud to present to you, the Wood Chimney Experiment! No science lessons today folks, just photos.

Students posing with their test chimneys.

SPOILER ALERT! On the left, you see our tried and true, the one who taught us so much, the Concrete Chimney Experiment. On the right, the Thermal Mass and Buoyancy Ventilation family welcomes their newest member, the Wood Chimney Experiment. Now let’s look at the building process.

The top and bottom insulation blocks are created by adhering two 6″ x 3′ 7″ x 3′ 7″ to make them 1″ thick. If you would like a reminder on why this insulation is necessary for the experiment phase and not necessarily for an actualized building you can read this post. The airflow cones are carved out so that they align with the airflow opening of the chimney interior chamber.

Student stapling gasket to foam insulation.

Here we’ve got the chimney walls coming together! Four sandwiches of ZIP sheathing, GeoFoam, and Wood Thermal Mass Panels all attached to create an interior chamber.

Three walls up, the fourth needs its sensors! The TMBVRP team thinks it would be absolutely wonderful to be in a space surrounded by edge grain wood that is also naturally ventilated.

Air-flow sensor set up for wood chimney.

The Sensirion airflow sensors will also be in this experiment. Incorporating how sensors can be attached within the chimney and their cords can make it out of the chimney without being squished is a crucial part of the design.

Students installing sensors into wood chimney.

Before the Wood Chimney Experiment interior chamber is sealed, the fourth wall containing the temperature signal sensors must be attached. The temperature signals, read about temperature signals here, will be sensed with thermocouples and heatflux sensors. Next step in the process will be building up the insulation surrounding the interior chamber.

Students with completed interior chimney. — Pre-Insulation

Completed wood chimney. — Pre-Insulation

The Thermal Mass and Buoyancy Ventilation team is aware they used to refer to these scientific apparatus as “Desktop Experiment’s”. Technically the inner chamber could stand on a desk, but a more appropriate name might be Carport Experiments or Taller than the Team Experiments. Let’s just call them the Chimney Experiments for clarity. These experiments are still the first and smallest experiments for the scalable Optimal Tuning Strategy. And look, the Wood Chimney Experiment is done! Batt insulation and 2″ GeoFoam walls encase the interior chamber and ZIP tape is used to seal the entire experiment.

Thank you to all who have encouraged and supported the Thermal Mass and Buoyancy Ventilation team! The team is very excited to have reached this point, but the work is no where near over. It will take time to learn a new data retrieval and analysis workflow for the new sensors. The team is excited to get to it, but first we are going to celebrate our Wood Chimney Experiment! Cheers y’all and STAY TUNED!

Tags: HomeLab, mass timber, natural ventilation, passive strategies, research, research project, Text Box Experiment, thermal mass, Thermal Mass and Buoyancy Ventilation, wood chimney experiment, wood grain

Preparing a Timber Pun for a Post Title

June 10, 2020

Live from HomeLab, it’s Wood Chimney Experiment preparation. The Thermal Mass and Buoyancy Ventilation Research Project team members are continuing their efforts to refine a passive cooling and ventilation system which can be deployed to public buildings in the rural South. Due to the fantastic results from the Concrete Chimney Experiment, the team is starting the Wood Chimney Experiment. They have developed an experimental method for designing and building chimneys which test the Optimal Tuning Strategy. They also have honed their data collection workflow and analysis. Now they can move on to testing how timber can work as a thermal mass. You can read about why we are using mass timber as a thermal mass here.

Section of the Wood Chimney Experiment design

The first step in Wood Chimney Experiment preparation is gathering materials. The team collected sensors that the Mass Timber Breathing Wall team is no longer using. Rural Studio has been growing its scientific equipment stock which allows for reuse between research projects. The TMBVRP team is inheriting data loggers, heat flux sensors, thermocouples, power supply, and airflow sensors. They will be using different temperature sensors, thermocouples and heat flux sensors, then are used in the Concrete Chimney Experiment. These sensors, like the GreenTeg Go Measurement System, will still deliver the proper temperature readings. This equipment is flexible and adaptable making it easily reusable between projects.

Sensors and power source for wood chimney experiment. — Reduce, Reuse, Re-sense!

Next, you might remember the team’s good friend, GeoFoam. GeoFoam is a type of dense expanded polystyrene foam usually used for earthwork under roadways. Both research teams have been able to use it as insulation for their experiments after the geofoam was donated to the Studio from a construction site. Remember, the team must cut smaller sections of GeoFoam from a huge 8’ x 4’ x 4’ block using a hot wire. The team was able to do so underneath the Morrisette Campus Fabrication Pavilion for a designated time and with faculty approval to ensure safety during the pandemic. They collected the rest of the batt insulation from storage in Brick Barn as well as materials for the structure of the experiment. Everything was hauled back to HomeLab for construction.

Next, the Thermal Mass and Buoyancy Ventilation team continued cutting down and shaping openings in the Geofoam. The top and bottom pieces of the chimney are made of two 6” thick pieces of GeoFoam that are adhered together as 1’ of insulation is needed for the proper U-Value for testing. The top and bottom pieces have cones carved out to ensure proper airflow. Resident King of Precision, Jeff Jeong, double and triple checks each piece of foam. This way the Chimney comes together like an airtight puzzle.

Student measuring foam insulation. — Gotta keep cutting that Geofoam

student cutting cone into foam insulation with hand saw. — Gotta keep cutting that Geofoam

The base for the chimney is constructed out of 2” x 4” lumber and plywood. The legs of this base are taller than the Concrete Chimney Experiment to match its height after being raised. Another difference in the design of the experiments is the walls of the interior chimney which the wood panels will be attached to. The walls for the Concrete Chimney Experiment are, from the chimney chamber outward, concrete panels, insulation, plywood, and then more insulation. The walls of the Wood Chimney Experiment will be pine panels, insulation, ZIP sheathing, and then more insulation. Notice Dijon doing his best to help in the photos below.

Student screwing legs for wood chimney experiment base. — We are all about the base.

Student hand planing wood for experiment chimney base. — We are all about the base.

Last, but not least, is pre-drilling holes for the concrete panels. The concrete panels will be screwed to the insulation, ZIP sheathing wall. There will be four walls to complete the chimney. Notice the grain direction of the panels. This edge grain allows for parallel heat transfer between the air within the chimney chamber and the pine panels. Not only is the Thermal Mass and Buoyancy Ventilation Research Project testing if timber works as a thermal mass but how the grain direction affects its efficiency as a thermal mass.

Student pre-drilling holes in wood panel.

Student using guide to pre-drill hole in wood panel.

The Thermal Mass and Buoyancy Ventilation Team is excited for the Wood Chimney Experiment to come together. So are the kittens! The team would not leave you without a HomeLab mascot update. While Dijon mostly naps, Rosemary is trying to get some construction experience to build her resume. They’ve had to tell her she is not OSHA certified, but she is fine napping a safe distance from construction now. It was not a hard sell. Stay Tuned to see the completed Wood Chimney Experiment!