Roofing a geodesic dome is a tremendous challenge on its own but, to find the roofer that roofed before and willing to do it, again, and for an affordable price, is a different story.
For our first dome in Leilani Estates, we found a local roofing company claiming they had previously roofed a dome. Well, yes, the one man who actually had an experience roofing a dome had a last-minute change of heart. He left right after they installed half of the Ice and Water Shield Membrane. I’m unsure what happened, but he vanished, and I never saw him again.
Do You Have What It Takes To Roof a Geodesic Dome?
Long story short, the two other guys were brave enough to come back with no prior experience roofing a geodesic dome, roofed the entire dome from a pdf manual, with drawings, and incredible detailed explanations. Thank you Denise, from NSD, for your thoughtfulness and attention to details on every nail and sticky stuff.
These guys were very young, so sweet, worked long hours, and on the end, did a terrific job. But, I just can’t resist to tell this story. The Grace Ice and Water Shield Membrane had a very sticky back-side. You suppose to cut it to size before peeling of the protective paper. Too bad I don’t have pictures of that moment, it was quite a site to see, still cracking up about it.
So, instead of cutting the membrane to more-or-less the correct size, they rolled it out and chopped off a large piece. They peeled off the protective paper on the ground and tried to go up on the ladder with it.
Both guys managed to glue themselves to the roof, tangled up with the ladder, and rolled into the membrane looking like giant burritos. We were all laughing and rolling on the ground…well, not the two guys. It was madness!!!
Roofing Second Geodesic Dome
Second time around was much easier to do. We found and flew in Whalen and Angie from Idaho. Boy, what a difference it was! Whalen a Spiderman, Angie a Cat woman swinging on the roof from one side to another.
We learned a few new things from them along the way. One, for example that it is an extremely hard and physical work to haul up the shingles onto the top of the roof. Most roofers just won’t do it. We had no idea.
Thank goodness for Home Depot Tool-rental, we were able to rent a winch lift, (we named it little Whalen) to haul up the roofing material. Wow! That was a life-saver for all of us!
Whalen and Angie finished within 12 days, did a fantastic job, and we all had some fun doing it. Thank you guys!
DID YOU KNOW?
Using a large, stripped-down, sofa cushion will prevent you from sliding off the roof, even in a vertical position. It’s a must-have tool for any roofer! Go figure!
Tips on How to Leak Proof Your Dome
Only improperly roofed geodesic domes’ roof leak. I can’t think of a dome shape that causes leaks. It’s round, it’s slopes all around and water flows down. If you have leaks in your dome, there is a ginormous chance that it is caused by improper flashing at some of your openings in the roof.
For example: around the vent pipe, a skylight, an extension where two different roof lines meet, or a dormer. Flashing those openings on any dome is not a colossally different than flashing on a square conventional house.
However, if they leak on your dome, they will leak on the regular house too, if shingled and flashed poorly. Although, the geodesic dome is very different from a conventional flat roofs, the entire dome is a big, round, curvy roof but, it can be shingled with the same techniques as a conventional roof.
However, no matter how experience you are as a roofer, before you begin, it is important that you read the instructions printed on the shingle wrapper.
Roofing Materials Used on Both Geodesic Dome
- Malarkey Legacy Asphalt shingle 36 sq.
- Interlayer – GAF Deck Armor (54”x223’/roll)
- Underlayment – Grace Ice & Water-shield High Temp membrane Malarkey Smart Start Shingles
- Malarkey Hip & Ridge cap shingles
- NSD Base drip edge for extensions – entex charcoal grey
- NSD Roof drip edge for extensions – entex charcoal grey
Our Geodesic Dome is a 4 Frequency, low profile, 50′ diameter dome located in the smack middle of the rainforest with high winds and seasonal, no-nonsense hurricanes. Therefore, using the best waterproof material is a no-brainer. We spared no expense on the roofing materials. We used a much higher quality, heavyweight shingles with a 40-year warranty.
Big No-No’s When Roofing a Geodesic Dome
Rule #1 – Do not under any circumstances use a ridge cap or Boston ridge on any non-vertical joint of your dome roof. Water goes under the ridge cap and into the joint the ridge cap is trying to protect. Your roof will leak!
Rule #2 – DO NOT under any circumstances use silicone or other caulks to waterproof the edge of any shingles. DO NOT seal the edge of the shingle around the skylights with sealants.
Rule #3 – DO NOT shingle between any 2 skylights. DO NOT shingle over the flashing on the bottom of the point up triangle skylights or the side flashing on point down skylights. This will void the skylight & dome warranties.
Continue to top or to base of cupola use sheets of 30# felt cut to 8’-10’ long. When cupola is sheathed felt and/or ice & water should be rolled up face wall 6” to 8” slots should be cut for venting around base of cupola. See venting chapter.Install felt with 2-3 inch over- laps—fold at points with fold facing down, (saves cutting & eliminates joint) and will not catch water.
Roofing a Geodesic Dome with Asphalt Shingles
Whalen shingled the point-up triangles first, using the fastener type and spacing recommended by the manufacturer. He was using a hook blade on his utility knife (came with the house components) to cut the edge shingles 1/2” from the edge of the panel.
He had to be careful when cutting the shingle on the panel, as he could have easily cut into the roofing felt. He removed the thin plastic strip covering the mastic patches on the back of the seal- down shingles.
They used a blue chalk and a chalk line (not the red – it is much harder to wear off), snapped a line along the 2 edges of the point up triangles 5” from the edge. Shingled the point-down triangles next, lapping the edges 5” past the panel edge onto the adjacent point-up triangles.
Then he nailed or stapled the 5” overlap section. This way, the overlaps laid flat. When finished with the base triangles pointing up, he begin working on the next course up.
Followed the same procedures as before. When I asked him, how does he know which way to lap a particular joint, he said, just imagine which way the water will run over the dome at that point, and make the point so it sheds rather than collect water.
According to the manual, at vertical panel joints on the upper part of the dome, do not cut the shingles.
- Do not apply a Boston or hip ridge cap to these joints.
- Do not caulk the gap between the shingles with roofing cement.
You should shingle the two triangles that have a vertical line between them by treating them as one “diamond” panel. Run the shingles over the vertical joint line at 90° to the vertical joint.
Shingling the Dome Extensions
- Cut angle on end and apply starter shingle next to dome. You can take a regular shingle & turn it 180°.
- Continue on to edge of extension roof with starter row of shingles.
- Attach step flashing over the starter shingle course.
- Cut angle on end for first row of shingles. Make sure the length of this 1st row of shingles is at least 6” shorter than 1st starter shingle.
- Apply this first row of shingles directly over starter row.
- Continue with 1st row of shingles, making sure shingle joints do not line up with starter row.
- Note the small cutoff pieces of shingles being used at the top of the point up triangles.
Shingling a Low Profile Geodesic Dome
We used planking/ scaffolding for the lower part of the roof. Be careful not to cut the shingles on the point-up triangles underneath. A mat knife with a roofing hook blade is used to cut the asphalt shingles.
For the 2nd row of triangles they are snapping a chalk line 5” down onto the 1st row of triangles. The upper shingles must overlap this line before being cut off.
We used ladders to shingle the middle section of the dome. After the point up and point down triangles done in the 1st row, and the point up triangles are done in the 2nd row, then the point down triangles on the 2nd row. It is important that the cut-off line is as straight as possible. We took our time and kept changing the hook blade.
After the 2nd row was completed, started on the 3rd row point up triangles. Note how the top 2 triangles of the pentagon are shingled as a diamond without a ridge cap over the vertical line.
NO ridge caps were used in the shingling of this dome. Final shingling on top of the vent cupola with cupola base flashing and fascia was applied.
