So what happened to hot tar roofing? Not that I need any roofing work done. It occurred to me when I recently saw a roofing truck. During the warm weather months I would always see roofing trucks towing a smoking tar cooker behind it but not anymore. Now I never see them.

So what have roofing contractors found as an alternative to rolling out tar paper and pouring hot tar over it?

Real hot tar - pine tar - went out some 40 years ago. Carcinogenic was the main reason, also expensive. Too bad - that stuff really worked, even though it was messy and dangerous to install.

Hot asphalt replaced it and it worked pretty well too, provided you paid attention to details when installing it. It wouldn’t tolerate ponding water like pine tar would so you had to be careful to provide adequate slope, among other things. Didn’t last as long as pine tar but it lasted long enough.

But hot asphalt is messy and hard to handle. Some 10 years ago we saw it phased out in favor of any number of new, superior materials. “Modified bitumen”, mainly. Comes in long rolls and the seams are heat welded. Less labor to install (single layer) and easier to get it right. Ponding is not an issue and the hot-mop shower pan business evaporated nearly overnight because it remains flexible and doesn’t stink up the house.

Various plastic sheet products had been around since the 60’s but were only used in really high end stuff like high rises due to cost. Now there are a bunch of different kinds and the price has come down to where they’ve become common.

Spray foam was going to save us all but it never really caught on. Excellent insulation qualities, very light, very quick and easy to install. Tolerates movement very well. Sticks tenaciously to whatever you spray it on - no nailing required.

But if you’ve ever left a styrofoam ice chest outside you know what happens to it - sunlight destroys it fairly quickly. The solution was reflective coatings of various types but they require regular maintenance and periodic re coating. Compounding the problem is the fact birds like to peck at it - heaven knows why. They’ll break through the coating in 100 different places and if the coating isn’t retouched almost immediately the foam underneath disintegrates.

I saw an old hot mop trailer sitting in a field last week. I suspect it will be converted to a BBQ trailer at some point, or perhaps hauled off for scrap.

Thanks Steve.