Thursday, April 4, 2024
HomeFactsHow To Insulate A Roof Without Attic

How To Insulate A Roof Without Attic

How To Insulate A Shed Roof

The Right Way To Insulate: Attics and Cathedral Ceilings with Batts

Care is needed to ensure that there is sufficient ventilation space between the underside of the roof deck and the top of the insulation. Insulating a shed roof is typically done using insulation below the roof deck and between the rafters.

Insulation And Finish System 07412 Metal Roof

Question: Some Older Buildings With No Roof Venting Seem To Be Ok Anyway

Our house was built in 1920 it has never been vented. The second story is finished with the insulation directly on the roof sheeting. This year, after 30 years, we had the house re shingled the roof deck was in perfect condition no problems anywhere.

If we had the the choice I would lean toward venting but because of the way the home was built it’s impossible but their has been no negative affect being unvented. – Jim

Reply: Some un-vented homes seem not to suffer, but not all: explanation and some warnings about un-vented cathedral ceilings on older homes


I agree that many older homes were often drafty-enough that combined with the good luck of no unusual indoor moisture source that they fared pretty well without more aggressive attic venting.

Building ventilation and moisture entry patterns change over the life of a structure

But one needs to be careful in drawing conclusions from those examples. The way buildings are used, heated, ventilated, insulated, and sealed changes over time. I have inspected homes that were more than 100 years old that had been in good shape as far as moisture problems were concerned, until energy costs led new owners to change the way the house worked.

Water from above or moisture from below was trapped in this vaulted ceiling described by an reader – more details are

One approach to that problem is to reduce excessive indoor moisture levels.

Lot of older homes vented naturally thru their wood shingle roof


Should I Remove Old Attic Insulation Before Adding New

Unless its water damaged or rodent-infested, you do not need to remove your attic insulation. Remember, if you are concerned about dust and air quality, you need to have your attic air sealed to separate the attic from the house before you add more insulation, otherwise youll just make the dust problem worse.

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Topping Up Your Attic

If your attic just needs a top up, you can apply a second layer of batting perpendicular to your current one. Just lay the new batting right on top of your current, between-joist batting.

When insulating, check to make sure that your insulation fits snug to the boards and joists for optimal energy efficiency.

Follow the same rules as if you were doing it from scratch and ensure that all spaces are covered and that there arent any gaps.

Get The Most Out Of Your Home With Proper Roof Insulation

Insulating A Roof Without Attic

You put a lot into keeping your home running. But there are small improvements many homeowners overlook that can make a huge difference. Insulation puts the money back in your pocket by protecting your home from the elements and lowering energy costs. Whether youre doing a weekend fix or folding it into a bigger home renovation, insulating your roof will pay off for years to come.

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What Kind Of Insulation Do You Use For Attic Rafters

Better materials for attic roof insulation are rigid foam boards and spray foam insulation. Spray foam: Technically known as Spray Polyurethane Foam or SPF, spray foam is most commonly applied in the space between attic rafters. It can act as an air and moisture barrier in addition to providing very high R-value.

Getting A Roof Replacement Now Is The Time To Update Your Insulation

Roof replacements are optimal times to update your attic insulation. If your roof was leaking, your insulation might have been impacted. Your insulation is especially likely to be water-damaged if your roof decking has developed wood rot, as this means moisture has been present in the roof for some time and has likely intruded on the insulation. Although, some types of insulation, such as closed-cell insulation, are not affected by moisture. You should replace other types of insulation when they get wet as they will not function properly.

Also, during a reroofing job, your roofer may need to add new ventilation to your roof to ensure you get the best life span from your shingles. If thats the case, they may need to remove some of your insulation anyway. Although, if the floor of the attic is insulated, a new vent opening can be easily cut into the roof deck without removing or disturbing the insulation.

Its highly beneficial to consider if you could benefit from better insulation before you get a flat roof installed. Once you have a flat roof installed, you may need to remove it to add new insulation.

Ready to reap the many benefits of proper attic insulation? Reach out to a roofer to discuss your attic insulation options through IKOs Contractor Locator.

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How To Insulate A Garage Roof Rafters

In a warm roof structure, the insulation is placed above or above and between rafters in order to avoid heat loss and energy transfer. If your garage ceiling is already finished then you will need to insulate it from the top.

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Does The Type Of Roof Cladding Matter

Roof Insulation Retrofit (Unvented roof)

You bet. Some roof claddings are made and installed in such a way that there is little to no air or vapor movement that encourages drying. Roof membranes certainly dont allow any air movement through them and many have very low vapor permeance . You would think that the lapped installation of asphalt roofing shingles would permit at least some drying by way of either air or vapor movement, but they dont. Asphalt roofing shingles constitute a Class 1 vapor retarder. Standing-seam-metal roofs are made of Class 1 vapor-retarding metal, and when theyre installed in direct contact with the roof assembly below, there is little to no air or vapor movement.

Roof claddings that are made or installed to allow air and vapor movement include barrel tiles, slate, corrugated metal roofing, and wood shakes and shingles. While there is no dedicated soffit-to-ridge channel in these materials and installations, there can be enough air moving through the installation and enough vapor permeance in the materials themselves to provide varying levels of drying potential to the exterior.

Conducting A Vapor Profile

A vapor profile is a qualitative method to determine what sort of drying potential a building assembly has, based on the vapor permeance of each layer of the assembly. There are four steps:

What’s your answer?above

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Can I Insulate The Underside Of My Roof

But the best solution is actually to insulate both the attic floor and the underside of the roof . In this way you prevent the heat from the rooms below escaping to the attic rooms above. At the same time, the areas below the roof benefit from increased comfort both during the winter and the summer.

What’s The Proper Way To Insulate A Roof That Has No Attic

I’d like to add insulation to the roof of an area of my house that has no attic, but an not sure the best way to go about doing so. I had originally thought I might be able to drill a few holes in the ceiling and blow in cellulose but have concerns about venting. For an attic insulation project I’ve seen that it’s typical to install ridge vents as to not restrict airflow between the soffit and some other vent higher up the roof line. This roof effectively has no venting. Being a 100 year old house with more than a few wonky renovations made in the past, this isn’t really surprising.

Anyway, since the room in question has a considerable amount of exposure to the outside, it’s always the coldest in the house. I added insulation to and encapsulated the crawlspace underneath which increased the temperature by 5 degrees, however I still have another 5 degrees to go so the temperature matches that of the rest of the house.

Will I do more harm than good by blowing in insulation? Is there a better way of taking this on? I’ve made a quick sketch of the roof in question.

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Locating Areas Prone To Ice Dams

One way to find areas prone to ice dams is to look at the roof after the first heavy frost in fall or light snow. Note where the snow melts first and find out what is under that spot. One common sight in such conditions is a horizontal melt line across the roof of a 1 ½ storey house, where the short knee wall meets the ceiling. Other places would be beneath a roof-ducted exhaust fan, plumbing vent, under a skylight and above a leaky attic access hatch. The best prevention for ice damming is to seal all attic air leaks and insulate thoroughly.

Dark wall finishes can absorb solar heat and cause warm convection wall currents that may be to blame for ice dams. Sealing the associated soffit vents may help reduce the problem. However, other venting may still be required to ensure that the roof space is properly vented.

Cons Of Structural Insulated Panels

Insulate Roof Without Attic  Attic Ideas

Vulnerable to moisture – Although SIPs are durable, they are not designed to get wet. They require some sort of vapor barrier or exterior sheathing that will protect them from moisture.

Requires a professional – SIPs are available in different sizes, but some that are larger in size require a crane with a professional installer.

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By Step Guide To Insulating Your Roof Without Attic

Roof insulation is a tricky and complex process that requires tremendous skills and experience to achieve effectiveness and efficiency through accuracy.

We recommend you to get the services of professionals rather than doing yourself. However, if your looking to insulate your roof yourself as a DIY process, we have prepared this step-by-step guide to give you a headstart.

  • First off, you have to set the scene. This includes that you have the right tools to access and insulate your roof and the required materials. These tools will typically include a measuring tape, a tough pair of scissors, a saw, a drill, and a nail gun. You also have to take care of any electrical wiring that is already present inside the roof rafters. If you are insulating the roof from the inside, make sure that you have large stands under you to support you while you are standing or moving. Similarly, if you are insulating from the outside, and standing on the rafters, make sure you dont put too much weight on the roof. Lastly, take care of the light as well. You should not be insulating your roof in the dark. Rather you should have ambient light present all the time during the roof insulation process.
  • You also have to wear protective suits, gloves, and goggles, if the material of your choice is dangerous for your health. For example, the shards inside the fiberglass can be hazardous. Similarly, if you are using wool for roof insulation, you should be careful as it can also be disturbing.
  • Installing A Vapor Barrier

    Batts-and-blankets insulation often comes with a vapor-retardant facing, and some varieties of rigid foam insulation need no extra barrier protection. For other types, it is a good idea to install a thin barrier of polyethylene on the underside of the insulation to prevent moisture from compromising your material.

    Always use unfaced insulation near flues and chimneys, as well as in instances where you are merely adding new insulation on top of old.

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    Insulating Your Attic Can Save You Money

    There’s no getting around it: If your house is in a cold climate, keeping it warm in winter is expensive. The Department of Energy predicts that prices for natural gas and heating oil will rise again this winter compared with lastand that’s after a year in which heating-oil prices rose sharply in most parts of the country.

    Sure, you can dial down the thermostat and get used to wearing bulky sweaters indoors to cut costs. But if you’ve got an unfinished attic, giving it proper insulation is one of the simplest ways to keep a lid on your heating bill this season. “It’s a DIY project you can tackle in a weekend, and the savings you’ll get add up every year,” says TOH general contractor Tom Silva. The Department of Energy estimates that a properly insulated attic can shave 10 to 50 percent off your heating bill. And it works the opposite way for warm climates in summer, it helps stabilize your house’s indoor temps to keep cooling needs in check.

    In a perfect world, you’d hire an energy auditor to tell you exactly how much protection you’re getting from the few inches of attic insulation you may already have and to pinpoint things like air leaks that you can seal to make sure your insulation will do its job well. But if you can’t afford to shell out a few hundred bucks for this service, never fear: We’ve rounded up all the most important know-how about attic insulation costs, products, prep work, and installation right here. Keep reading for the details.

    What Do You Do If Your Attic Doesnt Have Soffit Vents And You Are Unable To Add Them

    How to Insulate an Attic with ComfortBatt Insulation

    First, let me reiterate that I think you should use soffit vents as your intake source for attic ventilation. If your house has minimal overhangs that wont accomodate soffit vents, or you simply arent able to install them for some reason, then you have a couple of options to provide intake air inlets low near the roof perimeter. The two most common options are to:

  • Install low gable vents located above the top level of the attic ceiling insulation
  • Use eye-brow vents that are on the top of the sloping roof surface near the soffit/eave area.
  • Focus on the other ventilation you have in the attic.
  • If you are installing a new roof, consider a drip edge vent. This will allow air to come in under the edge of the shingles, and then enter the attic via a small slot/cut that is about 8 from the edge. Learn more here.

    Various exhaust vents can be used in conjunction with low gable vents and eye-brow inlets. For example, you can use ridge vents, mushroom cap vents, upper gable end vents/fans, high mounted attic fans, etc. Remember, your main goal is to get air moving through the attic by entering the attic space down low near the overhang/eave level and leaving the attic near the peak of the roof.

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    Can I Insulate A Garage Roof Myself

    Sure you can and it is very important to insulate the ceiling of your garage. This is particularly important for the warmer and cooler months. The insulation will keep the heat trapped in your home and allow you to save on your heating bill, during the cooler months. Also, remember to use thicker insulation and the recommended type is called R-40 insulation, this will give you the best insulation. You can install this insulation the same way you would install insulation to the walls of your garage.

    Lay the R-40 insulation in between the 2×4s of the wall frame and then you will sheetrock to cover the insulation. The sheetrock will provide an extra layer to keeping the warm air trapped in the walls of the garage. It is recommended that you pre-cut your insulation strips so that its an easier installation. Lastly, ensure the paper side of the insulation is against the conditioned side of the home.

    Start With The Attic Floor

    Stop using your attic for storage. Why? Because the simplest and cheapest way to insulate an attic is to add material to the floor. But if the floor is covered in plywood, you can’t stuff enough insulation beneath it to do the job sufficientlynot even in warm climates.

    Plan to pull up the flooring and layer new insulation on top of the old. With the floor gone, you’ll have to find a spot elsewhere for stashing those off-season clothes and that holiday decor.

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    Insulating The Attic Floor

    If you do not use the attic much, it is pointless heating this area. So insulating the floor of the attic is not only the best solution, but it is also the simplest and cheapest.

    In practical terms you can choose between mineral wool or insulation boards.If you decide on mineral wool, such as glass wool or rock wool, you will need to put down a damp proof membrane.

    If you would like to use the attic for storage, it is best to cover the insulation with some sort of boarding such as oriented strand board . Useful to know: there are insulation boards on the market that have this finish. If you would like to use mineral wool, it is best to lay this between the beams and framework that support the floorboards. Be aware that this approach can result in temperatures in the attic dropping below zero on cold winter days.

    Why It Is Important To Insulate A Garage Roof

    Insulate Roof Without Attic  Attic Ideas

    Garage Insulation for an open rafter garage is hugely popular as they are less expensive to build and the resulting roof is very strong and sturdy. This is also meant for those looking to better utilize the garages space and make it as inviting and efficient as possible. One way to do this is simply to insulate the garages open rafters to avoid inefficiencies that can often be attributed to attic heat loss. This is relatively simple roof insulation work that can be adapted for most situations. Also, it is important as it will save you money on your electric bill. Lastly, trapping the rising heat in your garage will allow your heating bill to be substantially less.

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