How to prevent Ice Dams with insulation Baffles is an important topic.

Before adding more blown-in insulation, attic baffles need to be installed.We will be able to completely cover the attic floor, which will give us the best performance from the new insulation.

We have a lot of old blown-in insulation that covers the attic floor.In the summer when the ceiling is warmer than the interior, the external walls near the top plate are an exception.See my FLIR ONE post for proof.

We will have a thicker layer of insulation with the installation of the baffles.We don't have to worry about blocking the vents because our attic can passively vent.The top floor of our house is supposed to be warmer in the winter and cooler during the summer.

We are only interested in discussing the edges of the roof that overhang the wall and the underside of it.

The best way to vent your attic is through the soffit vent.Cool air can enter at the bottom of the attic and exit via a roof vent.Venting is better than running an attic fan if your attic has enough vented area.

We will be installing attic insulation that will make sure there is enough air flow from the soffit vents.They will allow us to maximize our insulation without having to worry about air flow.There is no wind washing because the blown-in insulation stays put.

If your attic is properly insulated, there is healthy skepticism about the need for attic ventilation.I would prefer to make an honest attempt to get rid of the gasses in my attic.At best, I have a more comfortable home, but at worst I waste my time and money.

Soffit baffles are rectangular in shape and made of foam, cardboard, or plastic.They are installed in rafter bays to channel air into the attic.

I bought AccuVent baffles because I was confident that they would stay secure once installed.At my local big box store, the cardboard and foam baffles were too flimsy.

The diagram shows a view of the framing in the attic.The ceiling joists, rafters, and top plate are where we will be installing the baffles.

Baffles are usually installed while a house is being built.A low sloped roof and old insulation are two common obstacles.They make it hard to move around.

My house has a hip roof with a low slope, so there is very little room to maneuver in the attic.The top plate of the ceiling is cut to fit under the roof deck.Five inches of space is all it takes to install the baffles.

My solution was to make bricks of rigid foam insulation, attach them to the baffles with double-sided tape, and then use a small rake to push them into place.

I spray foam insulation into the cracks between the brick of insulation and the rafters after securing the baffle by attaching it to the roof deck.

I bought four sheets of foam from a big box store.I cut them in half in the parking lot because they didn't fit in my car.

I decided against buying the Foamular 150 because I didn't know it was less expensive.The impact resistance rating is the only difference between the two.The Foamular 250 and 150 can take 25 and 15 pounds per square inch, respectively.I don't know what that really means, but I think the 250 is better than the 150.

The easiest way to cut the rigid foam insulation is with a utility knife.It is best to use a snap-off utility knife.Score the insulation an inch deep and then hit it with your hand to break it.

My ceiling joists and rafters are both 16” on center, which should leave 14.5′′ inches, but each rafter is pairs with a ceiling joist that reaches to the top plate, so there is actually 13”My ceiling rafters are not exactly 16” on center.My blocks were cut to be 11.75” in width, which left 1.5” of wriggle room.

The blocks are 2” x 6”I made them deep enough to cover the top plate.

I used foam blocks and glue them together to make a height of four inches.There is about five inches of space between the top plate and the roof deck.

It is important to get the right type of glue for the insulation because it is made of polystyrene.It is important to buy the correct product for the job because many types of glue burn through it.

13” of width is available for my baffles in my rafter bays.The AccuVent baffles are so wide that they should be cut to fit.I trimmed them to 12” at their base to make room for my insulation blocks.

I did not trim away the excess width on each side.The ceiling joist overlaps the top plate in my rafter bay.I reduced the length of the ceiling joist by one-third.The remaining 1.75” was cut away on the opposite side.The photo above shows what this looks like.

I used double-sided carpet tape to affix the insulation block.I don't know if that's the best choice, but I could not find a glue that would stick to both of those materials.The double-sided tape is long enough for me to place the baffle in the rafter bay.

I use a small metal rake to move insulation in the attic.I pull the insulation away from the top plate and push it over the neighboring ceiling joist.

With the insulation gone, I push the baffle into the rafter bay so that it rests above the top plate.When I find a hole in the electrical wiring, I fill it with spray insulation.The top plate of an internal wall is where you may run into it.You will need to swap out the 4” insulation brick for a 3” brick if it is too tall.I had more rigid foam scraps from an earlier project.

Once the baffle is in place, I roll onto my back and staple the top-most part of it.Given the limited space, this is the best I can do.I tried using a hammer tacker for the extra reach, but found that there wasn't enough room for enough force to insert the staple.

I fill in the gaps with spray foam insulation.I think I waste some of the insulation because it takes me a long time to install each baffle.I am working away and it sets in the can.