Radiant Barrier Vs Spray Foam

Whether you’re structure a brand-new home or enhancing an old one, you have the right to use a combination of spray foam encapsulation with radiant barrier foil to save the heat out and enhance the comfort within your home. To obtain began, you’ll need to encapsulate the roof deck with 6″ open-cell foam, and also then insulate the attic and all the exterior walls. Foam alone is not sufficient though to store the radiant warm at bay, so you additionally need a good radiant barrier foil.

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The Air Void Problem

By combining radiant barrier foil via spray foam insulation you develop two defenses for reducing warmth flow into your home. Although utilizing them together with a normal roof is not as easy bereason the shingles are connected to the roof deck, which is associated to the foam, and there is no air gap in which the heat power can come to be radiant heat.

Radiant barrier foil is ineffective as soon as it doesn’t have an air area on one side. So you can’t simply glue it to the shingles and include the foam afterward. The obstacle shows only radiant warmth, which develops only in an air room. When you have actually an air room that enables radiant warm to form, you can use the barrier to reflect virtually all the warmth, not simply merely decrease it, as insulation does.

The Solutions

If you have a raised roof made from steel or concrete, you deserve to include the radiant obstacle below it, but over the roof deck. If you don’t, points are a little more facility and also deserve to obtain expensive. For instance, a raised roof is two or maybe also 3 times the expense of an average roof, and also you more than likely won’t be eager to change your roof just to be able to install radiant obstacle.

One idea is to deserve to produce a double-deck roofing mechanism as an affordable option. Anvarious other method is to add the foil via the cathedral ceiling technique and then include spray foam on height of the foil. Read listed below for even more details on each method.

Option 1: The Double Deck System

1. Install the bottom deck, leaving a 10″ gap from the fascia board to permit air to come in from the soffit vents and flow in between the 2 decks of the roof.

2. Add the radiant obstacle foil over the roof deck, ensuring that the foil side deals with up. A double-sided 48″ barrier is recommfinished.

3. Use a marker to mark the rafters on the foil.

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4. Install 1’x2′ furring strips, leaving a gap of at least ¾” between the roof decks.

5. Install a foil-backed roofing deck product of your alternative over the furring strips, producing the second deck, which you will certainly tie to the fascia boards.

6. Add the roofing felt and the shingles.

7. Spray foam the bottom of the first deck from inside the attic space as usual.

8. (Optional) Add ventilation. The rather restricted air space between the 2 decks doesn’t need a lot ventilation, but you have the right to consider installing efficient yet affordable wind generators that will certainly refresh the air between the decks, cooling and drying them.

The result will impush you. During warm summer weather when the temperature hits 100º and the shingles conveniently reach 170ºF, the lower deck will have actually an exceptional bottom surface temperature of under 110ºF. That’s bereason the air gap you’ve developed allows the radiant barrier foil set up under it to remove conductive heat and transdevelop the rest of the heat into radiant warm, almost every one of which have the right to then be reflected.

Building a double-decked roof in order to produce an air gap as defined above and also then utilizing the combined power of spray foam and also radiant obstacle foil will rise your structure expenses a little. But your home’s power performance will be increased dramatically, reducing your energy bills and at the same time enhancing the comfort level in your house. It functions for any kind of kind of residence. Do it and you won’t regret it!

Option 2: Retrofitting the Roofline from Inside the Attic

1. Install the single-sided radiant obstacle foil according to the installation instructions on this web page for Cathedral Ceiling Installations and also Wall surface Installations (they are basically the same procedures, simply various angles) via the foil side dealing with the exterior, towards the sun.

2. When it’s time to add constant insulation, forego the conventional batt insulation and instead spray foam on straight on the foil. *This just works because in Step 1 you’re going to produce the crucial air gap that the foil requires to job-related so on the inside you can include material appropriate on peak of the foil.*

If the spray foam is having actually trouble sticking to the foil layer, use a medial layer of foam board. Wedge the board into the cavity appropriate up against the foil and then spray the foam on to that.

3. Finish out the space if this is an inner area or if it’s an attic, simply leave it open.