Monday, February 8, 2021

Skylights in Pinecrest

Roofing in Pinecrest is always enjoyable. The homes are so diversified with the old and the new and the area itself is very . . . green!


And so, with things slowed down by the virus I decided to do this multi-project myself – that’s social distancing! Another reason I took it on was the nature of the work – skylights, roof coating app and a small flat roof replacement - that's my lane!

Skylights, Roof Coatings and Gazebo!

The customer wanted two 2’ x 4’ retrofit roof skylights installed. I do so love installing skylights from scratch. Each job is a little different and presents its own challenges. They also wanted to explore roof coatings on the T-shaped main roof. It was one of those tweeners – not enough slope for shingles, tile or metal but visible from the ground. The roof was probably a tar and gravel, originally, but I’ll bet it was done with river rock. You still see river rock on homes with a slope less than 2:12. They look great until they get dirty and then ...

This was a 1.5” insulated fiberglass built-up roof (BUR) with a mineral surfaced cap sheet. It is prevalent in South Florida but primarily a flat roof (low-slope) system not designed for curb appeal, especially when dirty. It was filthy, especially in the front where a row of old live oak trees hung over the carport. The carport slope was flat as was the section in back that formed the rest of the T. But the main house roof was visible and really detracted from what otherwise was a beautiful home. The BUR was only 11 years old so a roof coatings application made sense – extend the life of the roof, cool things off inside and curb appeal. There was also a gazebo roof to be replaced, only 250’ sq, so another project I could handle myself. Lastly, but the original reason for the call, there was a small leak at the chimney.

But First ... a Good Roof Cleaning

Before the skylight install and application of roof coatings the whole thing must be cleaned. When we say “clean” we mean biologically dead. All micro-organisms must die! I still prefer a 50/50 solution of water and liquid chlorine to do that while taking care not to kill any shrubbery. It’s done in sections, letting the chemicals do the work but very important to keep it wet. It must not be allowed to dry.

Roof Skylights ... From Scratch

First thing to do is get with the client and decide exactly where the skylights are going. I like to establish the corners and mark them by driving a 16d nail up through everything. This was an exposed ceiling with 1” x 6” tongue and groove so that part was relatively simple compared to hacking a hole through drywall and attic insulation. I’ve been there, done that plenty of times so . . . another reason why this was a good DIY, l o l. The nails project the corners to the roof so it’s just a matter of connecting the dots with a chalk-line. Most guys would have cut through the roof membrane with a hook-blade utility knife. That would take considerable time and effort through a hot-mopped BUR, not to mention 1.5” of insulation after that. Tools make the man, right? An old circular saw with a Big Blue demo blade cut through 2” of roofing for both skylights in 10 minutes. Then a switch to my good saw with a Diablo blade to cut through the wood deck. A little coaxing with a flat bar allowed all of it to be removed in two pieces – amazingly too easy . . .

From there a skylight installation really isn’t very different than any other protrusion, like a vent. The flange must be heavily caulked before setting into place and the whole thing is attached with the approved screws. I then sealed all around it with the Somay roof coating and fabric. Entire roofs are done this way – liquid applied roofing – applying a generous base coat, embedding the fabric and two or more topcoats. With the whole roof being done next the flanges would wind up with three topcoats. Basically you are creating your own membrane.

The little leak at the chimney was addressed the same way. Everything actually looked solid. There were no stains inside, no visible cause in the flashings or surrounding material so . . . I haven't heard a word about it since so, with a 3-year workmanship warranty on roof repairs, it's all good



Roof Coatings

Roof coatings, plural, because the main roof was actually three roofs. The main house had a 1.5/12 slope while the flat roof in back was slightly sloped and the carport was flat with some moderate ponding going on. Being 11 years old I did not think it was worth putting a top-of-the-line product on the whole thing such as a polyurethane or silicon at $250 or more per bucket. That was advisable for the carport considering the ponding and oak trees. A high solids water-based acrylic like Somay 842 Roof Mastic would be fine for the rest at just under $150/5gals.

The carport had to be done first. A water-based coating can go over solvent-based but not vice versa. First a coat of Tropical #996 Eterna-Sil Premium Asphalt Bleed Blocker primer for adhesion and to avoid discoloration. Then a generous coat of Tropical #924 Eterna-Sil Premium Silicone Roof Coating. That must be allowed to cure for a few days, not just dry to the touch, before lapping onto it with a water-based coating. So I primed the rest of the main roof with SOMAY No. 777 primer/sealer and applied two coats of SOMAY No. 842 Roof Mastic. Two projects down, one to go . . .

Gazebo Flat Roof

Tearing off the roof on the gazebo might be expected to be a little rough due to the exposed decking which requires enhanced fastener density. By Code, it should be anchored by hundreds of tin-caps. So, I broke out Big Blue again, cut it up into manageable chunks, took a swing at the middle section with a tear-off spade and it flew off in one piece. Sometimes a badly done roof is the easiest to remove, lol.

This roof consisted of a layer of 30lb felt, also not Code, which was barely nailed down and a mineral surfaced cap sheet that was only adhered at the perimeter. The seams were sealed with some sort of goop they probably got from the big orange box. Easiest tear-off ever! How it didn’t blow off with all the Cat 1 hurricanes that have been through here I don’t know but it had plenty of leaks. There was some rotten decking but, very surprisingly, not much. I put a standard torch-down system on it – two-ply Gafglas#80 base with a Ruberoid Heat Weld Granule cap. I do so love torch-down roofing in Pinecrest . . . in the winter. . .

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