Hi Steve,

Start by insulating the space between the basement ceiling joists with a sound dampening insulation like Owens Corning QuietZone fiberglass insulation. Next, you might want to consider using a soundproofing drywall such as QuietRock for the ceiling. You can watch and read more about QuietRock, on our website at (622) Builders’ Show Special.

Good luck with your project,

Attics, basements, and crawlspaces are the least frequented areas of a home, which is one of the reasons they often cause the most problems. A regular inspection can catch potential problems—like leaks, condensation, termite activity, or the growth of mold—before they become a major headache.

Attics can become virtual ovens in the summer, so work in the early morning or wait until a cooler time of year. Inspect basements after a heavy rain to catch any leaks. And don’t neglect the crawlspace under your home if it’s built off the ground on piers. While it’s not the most inviting place to spend an afternoon, early detection might save you thousands of dollars in termite damage or rot that would otherwise go undetected.

Here are some of the most common questions concerning problems with attics and basements:

Attics

Is it necessary to install a separate vapor barrier between the living area of a house and the attic or crawlspace?

No, a separate vapor barrier is usually not needed since any condensation should be able to escape from a properly vented attic or crawlspace. For more information, see our article on Vapor Barriers.

Should the facing on insulation in the attic or under the floor go up or down?

Install insulation with the facing toward the heated living area of the house. In the attic the facing should go down against the ceiling while under the house it should be up next to the subfloor.

Should you install a layer of faced insulation in the attic on top of the insulation that is already there?

No, always put unfaced insulation on top of existing attic insulation. Since the facing acts as a vapor barrier, it could trap moisture in the insulation. For more information, see our article on Attic Insulation.

If I install a second layer of insulation in the attic on top of the existing insulation, which way should it run?

If the existing insulation is even with or higher than the top of the joists, the new layer should run perpendicular to the joists. If the existing insulation is lower than the joists, lay the new layer between the joists.

How much venting does an attic require?

A typical house should have one square foot of vent for every 150 square feet of attic floor space. For more information on venting your attic, see our article on Adding Soffit Vents.

What size should an attic vent fan be?

An attic vent fan should be large enough to completely replace the air in the attic every six minutes. To determine the size needed, calculate the volume of your attic in cubic feet and divide by 6. This will equal the rated capacity of the attic vent fan in cubic feet per minute (CFM). For more information, see our article on Attic Ventilation.

Can you cover electrical wires and boxes in the attic with insulation?

While recessed ceiling fixtures should not be covered, wiring and ceiling boxes for surface mounted or hanging light fixtures can be covered by insulation.

How can I prevent condensation in my attic?

Condensation can occur when heated air from inside the house condenses on cold surfaces in the attic. This can usually be prevented by removing any sources of moisture in the attic, and making sure there is adequate ventilation in the attic. Always vent dryers and bathrooms fans outside rather than in the attic, and check to be sure that soffit vents under eaves have not become blocked by insulation.

Crawlspaces and Basements

How can I prevent mold and termites in of the crawlspace under my house?

Mold and termites can be a problem under homes, particularly in warm humid climates. Since both need water to thrive, start by checking for any plumbing leaks, condensation from ductwork, or rainwater seepage. Cover the crawlspace with sheets of 6 mil black plastic, overlapping them a foot and taping all seams. Run the plastic up the sides of the foundation walls with holes cut for the outside vents. Use a flashlight to inspect the joists and the subfloor periodically for signs of mold. Check the piers and foundation walls for mud tunnels make by termites. For more information, see our articles How to Prevent and Remove Mold, and Formosan Termites.

How can I add a bathroom or laundry room in a basement?

Since plumbing uses gravity to drain, you will have to install what is known as a “grinder pump” or “lift station” to pump waste water up to the level of the drain pipe leading away from your house.

What can I do to keep my basement walls from sweating?

Start by taping a one foot square piece of plastic to the wall and sealing it around all fours sides with tape. If moisture appears on the face of the plastic, the problem is condensation due to excess humidity in the air. If water forms behind the plastic, then water is seeping in from the outside. To prevent condensation, start by reducing the humidity in the air as much as possible by venting dryers and bath fans to the outside and eliminating any plumbing leaks. If problems persist, consider insulating the exterior walls or installing a dehumidifier. See below if the water is coming from outside the basement.

How can I stop a basement from leaking?

Start by being sure the land around your house is graded so rainwater is diverted away from the house. Install gutters and put extensions on existing downspouts. If that doesn’t help, you may have to excavate around the basement and waterproof the walls from the outside. For more information on basements, see our article Basement Refinishing.

Hi John,

Yes, you can vent a range hood through the roof using a 6” single wall pipe. You can buy the proper flashing to install it on a flat roof and a roof cap that has screen around it to prevent insects from entering. Be sure to extend the pipe up at least 2’ to 3’ to prevent snow buildup from causing problems.

From vaulted to tray to coffered, it seems like the sky’s the limit for ceilings these days. Specialty ceilings can add a distinctive design element to a room and make it feel larger than it really is. And when it’s time to sell your home, custom ceilings might be just the thing to make your house stand out from the crowd.

Cathedral Wood Ceiling

The cathedral ceiling in this home features tongue and groove boards framed with rough sawn beams. A layer of drywall was put up first to maximize energy efficiency and reduce noise. This was then followed by 1”x 6” pine boards and cedar trim. Track lights will be mounted in the slots on the ceiling, allowing the lighting to be adjusted to illuminate specific areas.

Painted Coffered Ceiling

Wood trim can be used to dress up a bland ceiling and give the room a more formal feel. This coffered ceiling consists of crisscrossed wooden beams applied over drywall with each square accented by a border of crown molding. A contrasting paint color was used on the recessed part of the ceiling to highlight the intricate trim work.

Wooden Barrel Ceiling

Ceilings can also be used to mirror the shape of other architectural features found in the room. This wooden barrel shaped ceiling follows the curve of the arched doorways found at each end of the room.

Circular Dropped Ceiling

Another interesting ceiling design is this circular dropped ceiling. It includes stenciling around the rim with a center medallion and hanging chandelier acting as the focal point.

Recessed Ceiling

Recessed ceilings—also known as pocket, tray (or trey), and bumped up ceilings—have become a common feature of new houses today. Typically these types of ceilings start with a lower border around the outer edge of the room and are then raised a foot or more in the middle. They may also include sloped or tiered designs accented by crown and other moldings.

Vaulted Ceiling

Often when an attic is converted into living space, the ceiling follows the slope of the roof to allow for additional floor space while providing enough ceiling height. It’s a good idea to flatten the ceiling out a few feet below the peak, however, to leave space for lighting, electrical wires, and ductwork.

Remodeling a Ceiling

While most specialty ceilings are incorporated into the plans when the house is built, ceilings in existing homes can be modified as well. Remodeling a ceiling requires careful consideration of the structural load carried by the ceiling joists before they can be removed. Once the existing ceiling has been taken out and the joists cut, work on the new ceiling can begin.

Any wiring, plumbing, or ductwork located above the room has to be taken into account and rerouted above the new ceiling. This can present a daunting task for the electrician and HVAC contractor.

Turtleback Wood Ceiling

This renovation project included turning a typical flat ceiling into a multifaceted turtleback ceiling over the expanded kitchen and den area. After the framing was complete, the beams were covered with painted 1”x 6” V-groove pine boards.

When installing solid wood, be sure to stagger the joints. A grooved block, made from a piece of scrap material, is used to protect the tongue when hammering the boards in place.

Tongue and groove boards can be blind nailed through the tongue so nail heads are not visible, or face nailed. Wooden ceilings may be painted or stained and provide an attractive alternative to drywall, though both the labor and materials cost much more.

Laminate Ceiling

Simulated wood ceilings made from laminate materials, such as Armstrong’s WoodHaven, are a do-it-yourself friendly substitute for natural wood. While the material costs are about the same as well real wood, the installation of laminate ceilings is much less expensive, since they come prefinished.

Stamped Metal Ceiling

Decorative stamped metal can make a striking ceiling with a unique character all their own. Products like Armstrong’s Metallaire™ ceiling panels are available in dozens of patterns and finishes from steel and copper to chrome and brass.

Other Tips From This Episode

Power tools used on Today’s Homeowner with Danny Lipford® are provided by Ryobi.

Even if your attic is well insulated, the folding stairs that provides access can be a major source of heat loss. They often are poorly sealed and provide only a thin piece of plywood to keep the heated air from escaping.

Begin by checking to see if the attic stairs close tightly then apply self-adhesive foam weather stripping around the perimeter where the plywood door meets the frame, except on the hinge end.

Once the opening has been sealed, it can be further insulated by building a foam box in the attic to enclose the stairs.

Materials for the project cost around $30. Here’s what you’ll need:

Materials List:

• 1 – ¾” x 4’ x 8’ sheet rigid foam board
• 1 – 2” x 30’ roll foil duct tape
• 2 – ¾” x 17’ roll foam tape weather stripping
• 1 – tube caulking (optional)

Be sure to use foil tape since regular duct tape won’t hold up to the heat in the attic.

Start by measuring the dimensions of the opening.

And the height the stairs protrude above the attic floor.

Using a utility knife with a straight edge as a guide, cut strips from the sheet of foam to form the sides of the box. For best results use a new blade so it will cut the foam cleanly. Make the strips an inch or two wider than the stairs extend above the attic floor.

Finish the cuts by bending the piece and cutting from the other side.

Cut the strips to length to form the box using a framing square as a guide then join the corners with foil tape. A bead of caulking can be applied as well to form a better seal.

Attach foam tape weather stripping to the top edge of the box to form a tighter seal. Cut a piece of foam the size of the exterior dimensions of the box for the lid. Tape the lid to the top of the box along one of the long edges with foil tape.

Clean the floor around the attic stairs so the tape will adhere well. Position the box over the opening, making sure it is square.

Attach the box to the floor around the outside with strips of foil tape then run tape along the entire edge.

A bead of caulking can be applied around the inside of the opening to provide a better seal.

Finally, remember to close the lid when you leave the attic.

For those who would prefer to purchase a premade cover, the Attic Tent™ is available in several sizes to fit different openings.

Could you wrap your house with a plastic vapor barrier on the outside before you brick it? If not why, because I’ve heard you can on the inside? I know you can use a Tyvek wrap, so why not plastic? - David

David,

When warm moist air cools, it can become saturated and release some of its water vapor in the form of condensation. If this occurs in the walls of your home, it may lead to the growth of mold or cause wood to rot. Vapor barriers, like plastic sheeting, prevent the passage of both liquid water and water vapor while housewraps, such as Tyvek Homewrap®, stop liquid water but allow water vapor to pass through.

In colder climates a vapor barrier is used on the inside of walls to keep warm moisture laden air from escaping during the winter. Installing a vapor barrier on the outside could cause moisture to become trapped behind it or condense in the walls.

In warm humid climates, the use of a vapor barrier on the inside is not recommended since it could have the opposite effect during the summer when the house is air conditioned. This is not as big a problem as in cold climates, however, since the temperature difference is not nearly as great.

Along the coastal southeastern United States, it is now recommended that a vapor barrier be omitted on the inside and put on the outside, though most builders use housewrap instead. In the middle regions of coastal Southern states, vapor barriers may be omitted completely. Other parts of the country, particularly colder northern states, should install a vapor barrier on inside walls and housewrap outside. Further information, including a map showing the recommendations for vapor barrier use, is available at the U.S. Dept. of Energy website.

Vapor barriers are not considered as important under floors or in ceilings, since attics and crawlspaces are usually vented to the outside which allows condensation to escape without becoming trapped.

My house attic is insulated, but I noticed that the attic over the carport is not insulated. The carport is open on two sides. It joins the main house and both attics are open. Does it matter if the carport attic is not insulated? - David

Hi David,

No, it’s not a problem at all. Since the air in the shared attic space is not heated or cooled and is vented to the outside anyway, it doesn’t matter if the area over the carport is insulated. In fact it is better that it’s not in order to lessen the possibility of moisture condensing in that part of your attic.

I have a new house with a metal roof and without a ridge vent. Please recommend a vent system without cutting holes in the metal roof.
Bjorn

Bjorn,

That would depend on the style of roof you have. If your house has a gable roof, you can install a vent in each gable then mount an exhaust fan in the attic behind one of them that is controlled by a thermostat. If you have a hip roof, you would either have to replace the existing ridge with a vented one—making sure the roofing and sheathing at the peak are cut back so air from the attic can escape through it—or mount a power vent fan on the roof itself, which would require cutting a hole in the roofing.

If you decide on a roof mounted fan, position it high up on the back of your roof, but not so high that it is visible from the front. Solar powered models are available that don’t require wiring, though they are more expensive than hard wired ones. Be sure the soffit under the eaves is vented so outside air can enter the attic.

Attic ventilation is crucial to the longevity of your roof and can help to lower your energy bill as well. Vents may be located in gables, under eaves, along the ridge of the house, or cut into the roof itself.

Hot air in your attic may not seem like such a bad thing in the winter, but it contains moisture that can condense and cause long term problems. In summer, heat in the attic not only makes your air conditioner work harder, but it also cooks roof shingles from the underside and reduces their life.

Continuous ridge vents have become popular in recent years for good reason. Since hot air rises, it’s important to locate the vent as close to the peak of the roof as possible, and nothing is higher than the ridge. While they come in a number of different types, one system uses a fiber mat laid along the ridge with shingle tabs mounted over it. A narrow slot cut in the ridge allows hot air in the attic to escape while keeping insects and rain out.

In order for ridge vents to be effective, you need a supply of fresh air coming in from the soffit under the roof’s overhang. Soffit vents are available in a number of styles including round and rectangular metal vents, integrated vinyl soffit vent panels, or continuous trench vents. By combining both soffit and ridge vents, you can create a constant flow of cool, dry air through your attic in both winter and summer.

See Also:

• Adding Soffit Vents

How well insulation works is expressed by its R-value, which measures resistance to the flow of heat. The higher the R-value, the better it insulates.

How Much Is Enough?

The amount of insulation recommended for your home is dependent on where you live, but here are some general guidelines:

• Attic: Houses in a cold climate should have a minimum of R-49 in the attic, which is equivalent to approximately 15″ of fiberglass insulation. Warmer climates only require an R-38, or about 12″.
• Walls: While wall insulation is limited by the width of the studs, different materials provide higher or lower R-values. Fiberglass batts for standard 2×4 walls are now available in low, medium, and high density products that range from R-11 to R-15. Sprayed foam insulation in the same wall cavity can range from an R-14 to an R-28 depending on the product that is used.
• Floors: While there are additional considerations—such as venting and moisture problems—to take into account when you insulate under floors, the United States Department of Energy recommends an R-25 rating in cold climates and an R-11 in warmer parts of the country.

Installation

You can hire a professional to blow in loose insulation, or you can install rolls and batts yourself. If the attic isn’t insulated, cut the batts to fit in the space between the ceiling joists. If there is already insulation up to the top of the joists, roll out the new batts perpendicular to the joists.

If you choose to do the work yourself be sure to wear a long sleeve shirt, gloves, eye protection, and a particle mask. Don’t attempt to work in the attic during the heat of the summer, and be careful not to step through the ceiling!

More information is available at these U.S. Department of Energy websites:

• EERE Energy Savers - Insulation
• EERE Consumer’s Guide to Insulation and Air Sealing

Related Articles

• Getting Adequate Attic Insulation
• Attic Insulation
• Prevent Fiberglass Insulation Itch