timber research

Getting Down to the Details

November 9, 2020

Live from behind a stack of full-scale detail drawings, it’s the Thermal Mass and Buoyancy Ventilation Research Project Team! Lately, the team has been investigating all details inside and out. Starting out with material pallet and ending up at chimney flashing, the team is kicking it into high gear.

Cladding Material

1/4"=1' model of pods showing scale figure in cooling patio underneath — Iteration 1 Model

iteration 2 1/4"=1' model birds eye view — Iteration 1 Model

Unsurprisingly for a project so focused on the interior systems, it was difficult to make decisions regarding cladding. Initially, as seen in previous models shown above, the team experimented with separate cladding systems for the chimneys, Cooling Porch ceiling, and exterior walls. For iteration 1 of the test building design included a timber open-joint cladding system wrapping every surface. Next, for iteration 2, the cladding system wrapped only on the exterior wall faces of the buildings and the adjoining chimney faces. However, thin sheet metal covered the roof, cooling porch ceiling, and the chimney faces which touch those surfaces.

timber cladding + stacked timber walls and benches

The consistent cladding of iteration 1 appealed better to the monolithic nature of the SIPs structure. It also reinforced the importance of the chimneys to the buildings as a whole from the exterior. From there the team began to test if the timber was the correct mono-material for the test buildings. Seen above are renderings testing different materials for the cladding, columns, retaining walls, and benches. It is important to view these materials as they interact in the Cooling Porch. While sheet metal and polycarbonate cladding options may look more monolithic, timber is a low carbon material that better represents the heart of the project. In some cases, timber as a building material acts as a carbon-sink meaning it stores and processes more carbon than it produces. This of course relates strongly to the passive goals of the Thermal Mass and Buoyancy Ventilation Research.

Recycled Retaining Wall

Now the team is settled on the timber cladding, but they are not convinced of the retaining wall and bench materials. These aspects want to be a more earthen material as they rise from the ground towards the test buildings. After investigating rammed earth and concrete, the team wanted to find something more stackable. Concrete and rammed earth are beautiful, but they require formwork which requires more time. Something stackable will give the team more flexibility as well as members are movable.

Thankfully, down here on Highway 61 road work is being done to remove a load of 8″ x 8″ x 8′ stackable concrete barriers. The TMBVRP team is getting their hands on some of these reusable members and are calling around to local highway departments to find more similar materials. If they find enough, they will have a durable, stackable, and reusable material for their Cooling Porch. They can also use the old sidewalk pieces as a mosaic, ground material for the Cooling Porch. Above are drawings showing the use of these recycled materials.

Structure and Detailing

laptop screen showing Joe Farrugia on video call with students — living lengend Joe Farrugia on Zoom

For the past three weeks, the team has been meeting consistently with Structural engineer Joe Farrugia. He is guiding the team through lots of math to size their columns. While the gravity load on the columns is extremely manageable, the wind load is more difficult. The test buildings height means they will face more wind load than a structure this size typically experiences. However, Joe is confident that the structural system the team has chosen is doable with the correct column sizing.

While the team is attempting to draw every detail of the test buildings, they’ve found the trickiest spots to be around the chimneys. Making sure water moves off the roof consistently and air moves behind the ventilated screen is crucial. The TMBVRP will spare you the pain of walking through each flashing bend and board cut. Struggles emerge when the chimneys converge with the angled roof, but it’s very doable with lots of thinking, drawing, and redrawing. Then Andrew Freear and Steve Long, come in to save the day because how you’ve redrawn it five times is still wrong. Lots of covered wall reviews later and the TMBVRP team is on their way to compiling all the details in a digital model and drawing set.

students and professors gather in front of a wall full of detail drawings

Looking forward to keeping this momentum going, the TMBVRP can be found in Red Barn from dawn to dusk. Feel free to bring by some late-night snacks but for now thanks for TUNING in!

Tags: Cooling Hearth, Cooling Porch, details, natural ventilation, passive, passive strategies, recycled materials, SIP, Structure, thermal mass, Thermal Mass and Buoyancy Ventilation, timber research

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

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!