We are turning our roof into an unvented roof assembly by raising the roof and blowing in SPF. We are planning to leave the existing vapor barrier down but remove the fiberglass batting and then adding 6" of SPF in all the cavities, to completely seal and insulate the house. Should we have any concerns about doing it "upside down" and not spraying the foam directly to the underside/sheathing of the roof? http://www.youtube.com/watch?v=ggLAUsiuI_o&feature=youtu.be
Apply coating when the roof is dry and the sealant has set. You will be using a 9-inch heavy-duty frame, ½-inch paint roller for spreading coating on roof or 1-1/4-inch roller for dipping in pail, and a 5–to-6-foot extension pole. Use a 3/4-inch roller with basecoats and emulsions. Map out your roof and make each pail fill that area. See Elastek Product Sheets for recommended coverage. An inexpensive 3-inch or 4-inch brush should be used to reach areas not possible with a roller. Use a stiff paintbrush for applying 103 Crack & Joint Sealant.
What more is that we also think it is one of the most durable among liquid roof coatings on the market. It can last for several years, working continuously in protecting your roof from outside elements, such as dust, leaves, twigs and debris that would otherwise damage your roof. When it happens, your roof might have leaks and cause discomfort inside your RV.

The Gardner 4.75 Gallon Heavy Duty Foundation Coating The Gardner 4.75 Gallon Heavy Duty Foundation Coating is ideal for sealing concrete block and poured foundations fence and deck posts retaining walls and metal surfaces. Its high penetrating seal resists damage and deterioration due to moisture and insects. When applied properly this solvent-based asphalt coating helps prolong the life ...  More + Product Details Close
SPF insulation applied by professionals is usually described as either a high- or low-pressure foam and is available as either open- or closed-cell. Each type has advantages and disadvantages depending on the application requirements. The comparison chart below can be helpful in explaining or understanding which type of SPF insulation is best suited to a specific application.
I don't know if it's common or uncommon, but installing a layer of rigid foam above your roof sheathing in order to interrupt thermal bridging is always a good idea, and is preferable in all respects to a roof assembly without any rigid foam above the sheathing. If you decide to install rigid foam above the roof sheathing, you shouldn't use closed-cell spray foam under the sheathing; either use open-cell spray foam (which is vapor-permeable) or a fluffy insulation like cellulose, mineral wool, or fiberglass (any of which will allow the roof sheathing to dry to the interior).

How Much Is Spray Foam Insulation


Acrylic coatings are typically applied in two coats, with the second running perpendicular to the first. 1 gallon per 100 square feet is a good estimate for these coatings, as they do not need to be applied nearly as thick as many other coatings. These coatings can be sprayed or roll-applied. Acrylic coatings generally require a re-coat within 2-3 years of application.

Spray Foam Roof Insulation

×