We inherited a foam roof that was leaking even before we purchased the home, but didn't find out until we took down a wall (that shouldn't have been there) to find molded wood. We also discovered puddles of water underneath ceramic tile which was also removed during our kitchen renovation. (Imagine smashing tile and getting splashed with water, wondering - WTH is going on here?!!) During a 3-day rainstorm, we noticed a soaking wet vintage chair and I immediately blamed the kids ;) The following rainstorm after that, we saw where the leak was coming from and only then we had our AH-HA moment. Sorry kiddos! The roof was hardly seven years old, and the fly-by-night roofing company was long gone. We found Yelp reviews with consumers all up in arms, but oh well - that's another story.
Researching DIY Foam Roof Recoating
There wasn't too much information about recoating a spray polyurethane foam-based (SPF) roof system, so I figured I would share why I tried. Quotes were rumored in our 'hood to go for anywhere between $5,000-$10,000, so this was one of those projects I wanted to figure out. Another Eichler owner, Barry Brisco of San Mateo CA, shared his experience recoating on the boards at Eichler Network, which gave me some hope and guidance with this project. I tried to locate the Apoc 252 elastomeric product he referenced, but Pacific Supply in Oakland no longer carried it, so I then got tips from our awesome neighbor located conveniently across the street, Brian Maher, who recently DIY'd his recoat over the past month.
Materials and Tools Used for the DIY Foam Roof Recoating on Our Eichler
I went with the Lowe's sourced BLACK JACK Ultra Roof 1000 White Siliconized Elastomeric Reflective Roof Coating (10-Year Limited Warranty) and decided to spray using the Graco Magnum X7 Airless Paint Sprayer, loaned to me by a fellow DIY junkie Johannes Sjoeberg @sagamadison - thanks a ton!
At Lowe's, there were two other main options, a BLACK JACK 700 which had a 7 year warranty, and a BLACK JACK Premium Silicone Waterproofing Coating which had a 50 year warranty ($200/bucket) which seemed a bit overkill, and I wasn't all that familiar with silicone products. The 10 yr product seemed to fit the bill at $83/bucket and was acrylic based, so I knew cleanup would be manageable.
Steps for the DIY Foam Roof Recoating on Our Eichler
- Blow all the debris off the roof.
- Power wash all the dirt and grime.
- Patch cracks, joints, seams, then spray coating
DIY Foam Roof Recoating Step 1: Blowing Off Loose Debris
DIY Foam Roof Recoating Step 2: Power Washing Surface
I borrowed a power washer, also from Johannes @sagamadison which was a 2000 psi unit that I hauled up the ladder to the roof. It worked wonders and took me a few hours to complete the cleaning. The difficult part was dealing with ponding on the flat part of our roof, where the dirty water just sat there begging to be left alone. Spraying the puddles of water around seemed, at times, counterintuitive because I was just adding more water to the pool, but in the end it worked. I tried the leaf blower, but as you blew, water would evaporate and leave muddy streaks. A better system was to blast it with the power washer all the way to the gutters or off the edge, while someone also helped to push-broom it. I thought about wet-vac'ing but I wasn't in the mood to haul up yet another piece of equipment onto the roof, and dig around for a 3-way outlet extender.
DIY Foam Roof Recoating Step 3: Spraying the Coating
The coating needs to be applied to a dry surface (although a competing brand mentioned to spray a mist of water that could allow for a slower drying time if needed in high temps), so this isn't one of these projects you can start at the crack of dawn because the condensation first needs to evaporate. (Yes - I can sleep it!)
I had prepared six 5-gallon buckets of coating, but planned on only using five. I was a little nervous that the sprayer wouldn't handle it because the specs on the competing product (Apoc 252) required a 0.2-0.3 tip using 3000-4000 psi at 4 gpm, and mine had a 0.17 tip (max suggested) and put out 3000 psi but it worked just fine.
I had a long 70' hose which made it convenient because that way I wouldn't have to haul up 5 gallon buckets onto the roof (I had already almost killed myself bringing down the pressure washer).
Total Cost of One Coat of Roof Coating:
One full coat took about 5 buckets, so $85 x 5 = $425
Paint sprayer: $500-700
Power Washer: $200-400
All in you could be looking at $2,000 for two full coats and buying the tools.
Two coats should be applied. I managed to spend a few hours on Saturday cleaning the roof, and Sunday spraying, so you could tackle it in a single weekend, but I probably only put in eight hours in total for a single coat.
Good luck if you are going to tackle this project!