Cosmetic Treatments on Dome Exteriors

There are three issues concerning the exterior of domes.

1)     protecting the shell

2)     windows and doors

3)     cosmetic finishing 

Protect the shell from degradation and water intrusion by sealing it so that UV and full spectrum light from the sun doesn’t destroy the airform or foam underneath. Another concern is impact damage from storm debris. We investigated several methods and products, and found them to be overkill in both effort and cost. Just a simple repair from a storm can be cost effective over the cost and effort of chain shelling.

We chose to paint the airform with elastomeric roof coating, this helps the airform stay protected for decades. This has the resilience and the UV protection needed.  We did another layer with STO synthetic stucco mixed with the paint 50/50 for more durability in a harder finish. It can be installed by one person, either using a small hand held texture gun, large hopper unit or by hand with a trowel or roller. It seemed to give the right texture to smooth out seams and minor cosmetic blemishes. There are places where more work was needed to make it look perfect. We then used the STO 100% to fill and level those areas that were too deep for the paint mix. We chose to keep the white color because of the Florida sun, for reflective qualities. Other people can choose to add pigment to make a color statement or to help blend into the environment. 

In our design we chose bump out augments, increasing the interior floor space and keeping a more organic shape with our 6’ half round windows. This worked better than adding conventional dormers which are cuts into the airform instead of formed into the airform. The only thing augments can cause are some wrinkles around the rounded sections of the windows, because of the stress on the airform during inflation. We dealt with this by filling these creases with foam, shaping and sanding, then trowelling smooth with the stucco. 

Since our windows are finished flush with the face of the augment, we chose a trim treatment from a company called Coral Light in South Florida. Their product line is flexible and rigid foam trim for interior and exterior applications. They offer a huge selection of designs and profiles in several finishes such as wood and faux stone. We chose a 3” round in a coquina finish and colored it white to match the windows, it complements our decorating scheme and window design perfectly. It became a drip edge for the windows and sealed the airform flashing behind it from blowing rain and wind damage.

 We feel that our choices were the best for our situation here in South Florida. Finishing the exterior of the dome wasn’t as overwhelming as we originally thought; the products we chose made it fairly cost effective.