Category A HOUSE

If you walk down the caulk and sealant aisle at any well-stocked hardware store or home center, it’s easy to feel overwhelmed by the variety of products available. For quite a few years now, the terms “caulk" and “sealant" have been used interchangeably. In techni­cal terms, sealants are supposed to be more flexible than caulks, meaning that they are able to expand and contract with the move­ment of materials. But even caulk and sealant manufacturers have different definitions for these materials. For this reason, it’s smart to ask local builders and knowledgeable building-material suppliers which caulks and sealants are recommended for various jobs.

Although manufacturers haven’t cleared up the distinction be­tween caulks and sealants, they have improved their labeling with regard to specific applications. For example, “painter’s caulk" is an inexpensive latex-type caulk that is primarily used to fill gaps in and around interior trim prior to painting. Caulk that is labeled “for kitchen and bathroom use" is waterproof and will adhere to tile, porcelain sinks, acrylic shower units, and other surfaces found in those rooms. Silicone and urethane sealants are usually more expensive than acrylic or latex-acrylic caulks and are primarily used in exterior applications where extra durability, flexibility, and weather resistance are important. But be aware that acrylic paint does not adhere to some silicone caulks. Check with your supplier to see if your paint and caulk are compatible.

Caulks and sealants can be useful on small openings

For filling small gaps (up to lA in. or so), caulks and sealants sometimes work as well as, or better than, foam. A good sealant has suffi­cient flexibility to maintain a seal even though the joint expands and contracts slightly. For advice on selecting caulks and sealants, see the sidebar on p. 199.

If you plan to use caulk or sealant to fill a gap wider than /4 in., it’s a good idea to insert a backer rod into the joint before you apply the sealant. Available where caulks and sealants are sold, backer rod is made from dense, compress­ible foam. When wedged into a joint, it helps seal the area and lets you apply a thinner bead of caulk or sealant.

Most locales have an energy code that defines how well insulated your house must be. Check with the building inspector in your community for this information. Rather than requiring so many inches of fiberglass or rigid foam, these codes define insulation requirements in terms of R-value, or resistance to heat flow. The higher the R-value, the greater the insulating value. For example, code may require that exterior walls be R-11 or R-19. As it turns out, a 2×4 wall with fiberglass insulation designed for a 31/2-in. wall has an R-value of 11. Denser batts that increase the R-value to 15 for a 2×4 wall are available. A 2×6 wall with 5V2-in.-thick fi­berglass has an R-value of 19. Don’t try to stuff R-19 fiberglass batts into a 2×4 wall, though. Carpenters say that’s like trying to stuff a 1,000-lb. gorilla into a 500-lb. bag. It just doesn’t work.

Remember—code requirements set minimum standards. As far as building materials go, insulation is relatively inexpensive, so it’s often cost effective to install more insulation than what is required by code. A house with lots of insulation (in the attic, for example) will not only reduce your heating bill for years to come but may also save you money up front by reducing the size of the heating or cool­ing system you need to install!

to apply two beads of silicone sealant beneath their bottom plates. If this was not done for some reason, you can run a heavy bead of seal­ant where the inside edge of the bottom plate meets the subfloor.

Once the walls are framed, it’s important to install insulation in the sections that will be inaccessible after the wall sheathing is applied. As discussed in Chapter 4, these areas include the voids or spaces in the framing for corners, channels, and headers. Likewise, pay attention to areas where tubs and shower units will be in­stalled in exterior walls. You don’t want the stud cavities in these areas to be blocked off before you have a chance to insulate them.

Part of a sealing strategy may include house – wrap. Modern housewraps, such as Tyvek and Typar, are wrapped around the framed exterior

when it is compressed. It’s better to insulate narrow spaces with foam insulation. The spaces between the window or door jamb and the rough opening can also be “foamed,” but be careful not to apply too much expanding foam in those areas. Because jambs are usually only 3/4 in. thick, the foam’s expansive action can cause them to bow inward.

AROUND PLUMBING AND ELECTRICAL LINES THAT PASS THROUGH EXTERIOR WALLS. If your house has exterior faucets, seal the hole around each one with foam insulation. Holes for outdoor electrical lines and outlet boxes in exterior walls should also be sealed.

When you think about sealing a house, remem­ber how much frigid air can go through a small opening in a sweater or a jacket. Even a tiny hole in a woolen mitten can make your finger numb with cold. The same thing can happen in a house. We had single-glazed, double-hung windows in that old prairie home where I grew up. In the spring, the windows were nice—we could open them wide to let in fresh breezes and the songs of meadowlarks announcing warmer weather. In the winter, though, that loose-fitting sash was a fright. My mother gave us thin strips of cloth to stuff between the window frame and

Don’t worry; we haven’t suspended our home­building work to look through the L. L. Bean® catalog. But what you already know about sweaters, windbreakers, and raincoats will help you understand the way sealing, insulating, and moisture-protection treatments work together in a house.

Start with a sweater and a windbreaker—just what you need to wear on a cold, windy day. A house exposed to frigid temperatures and icy winds also needs a sweater and a windbreaker. Insulation, exterior siding, and housewrap provide this protec­tion. In fact, housewraps like Tyvek and Typar act like a Gore-Tex® raincoat, blocking wind and water while still allowing vapor to pass through. This helps prevent moisture buildup, both in our clothing and inside the walls of a house.

As we work through the steps ahead, you’ll see that there are different sealing, insulating, and ventilation tasks that need to be done at different stages of the construction process. Pay attention to the tasks associated with each phase
of construction and your house will repay you with maximum levels of comfort, longevity, and energy efficiency.

Sealing, Insulating, and Ventilating a House

The old house I was born in still stands out there on the prairie. When I was a child, the house was simply unheatable in the wintertime. We defi­nitely spent more dollars trying to heat the house than we did on the mort­gage. Nowadays, the house has new doors and windows, insulation in the ceiling, and a real heating system—not just an old iron stove in the kitchen. But there are still plenty of cracks and gaps in the walls for those ever­present western winds to howl through.

Thankfully, we don’t build houses like we used to. Today, there are materi­als and methods available that allow us to design and build energy-efficient houses that hold heat during the winter and keep it out during the summer.

But attaining high levels of comfort and energy efficiency is not always a simple feat. In fact, it can be the most technically complex aspect of building a house.

The products that we use to seal, insulate, and ventilate houses may do more harm than good if they’re not installed correctly. Common problems include poor indoor-air quality, peeling paint on interior and exterior surfaces, moldy bathrooms, and rotten wood in walls and ceilings (see the photo on p. 196). Sometimes we solve one problem (such as cold air infiltration during winter months) and cause another (high concentrations of stale, humid indoor air, for example). And thanks to the significant climate differences in this vast country of ours, what works in Maine may be ineffective in Texas.

Although there is no standard approach to building a tight, comfortable, and energy-efficient house with good indoor-air quality, it’s not difficult to achieve those goals if you understand how a house works in terms of insula­tion, airtightness, and ventilation. This is especially true with the basic, afford­able houses that Habitat builds. This chapter explains the concepts, materials,

and techniques to make your house comfort­able, healthy, and energy efficient no matter what the temperature is outside. To expand your knowledge, see Resources on p. 279.

Before we dig into the technical details, here’s a final thought to keep in mind as you tackle the sealing, insulation, and ventilation work on your building project: Try to keep everyone aware of these important issues.

When houses were built with simple materials, they were both leaky and energy inefficient. People working in the trades didn’t really need to understand the work of those preceding or following them. To build a safe, energy – efficient, nontoxic house, everyone involved in its construction must have more knowledge and work together. Otherwise, a house that was perfectly sealed and insulated can be left riddled with holes by a plumber, electrician, or heating contractor who was “just doing his job.”

Chamfering the tops of railing posts or the ends of beams is a nice finish­ing touch you can add when building a deck or a porch. A plain, square-topped post looks clunky, but in a few minutes’ time you can give the post a more dis­tinguished appearance. All you need is a Speed square and a circular saw. For best results, use a sharp, fine-toothed blade on your saw. If you haven’t tried this technique before, practice on a spare length of 4×4. Also, you may find it easier to make chamfer cuts “on the flat," with the 4×4 set on some saw­horses. It takes a little more experience with a circular saw to chamfer a post that’s already installed verti­cally. Here’s how to chamfer a post in four simple steps:

LAY OUT THE CHAMFER LINES. As shown in the photo above, a pair of lines, spaced about 1 in. apart, should extend around all four sides of the post. The upper line represents the length of the finished post.

CUT THE POST TO LENGTH. Make a square end cut to sever the post along the upper layout line. Two cuts from opposite sides of the post should do it.

MAKE THE CHAMFER CUTS. Loosen the angle-adjustment knob or lever on your circular saw and adjust the cutting angle to 45 degrees. An exact 45-degree angle isn’t necessary, but be sure to tighten the adjustment securely. Now make an angled cut along

each side of the post, following the layout line. If you have trouble maintaining a straight cut, clamp a Speed square to the post to guide the base of your saw. Another trick for ensuring a smooth cut is to retract the blade guard with your forward hand before you start to cut. SAND THE POST SMOOTH.

Use some 120-grit sandpaper to smooth out any rough areas. You can also slightly soften sharp corners.

The most difficult part about building any rail­ing is making sure the posts are well secured to the deck or stairs. Remember: People will be leaning against the railings, so make them strong. A post that extends up to the roof fram­ing will be solid and secure. Short posts that support only the railing are more of a concern. Railing posts should be evenly spaced across a deck or porch and no more than 6 ft. apart. A good height for a railing is 36 in. to 42 in.

I like to notch railing posts to fit against the rim joist (see the photo below). A notched post,

installed with a couple of ‘/s-in. or ‘T-in.-dia. carriage bolts, makes for a strong and attractive installation. For a 4×4 post, make notches 1/2 in. deep and long enough so the notched post can cover the full width of the rim joist. If the top of the railing posts won’t be covered by a 2×4 or a 2x 6 cap, consider letting those posts run a few inches higher than the top rail and chamfering the top of each post. This technique, explained in the sidebar on the facing page, can enhance the appearance of any railing.

Posts for stair railings can be fastened to an outer stair stringer. Use carriage bolts rather than screws for stronger connections. At the base of a long stairway, where extra strength is required, the post can be anchored in concrete or to a steel post base embedded in concrete. RAILS AND BALUSTERS. Once the posts are installed, cut and install the rails. I use PT or cedar 2×4 rails for most of my deck railings. They can be fastened to the outside or the inside of posts, depending on the overall design of the railing. Some builders even notch their posts to accept the rails. No matter which method you choose, secure each rail-to-post connection with two 3-in. deck screws. If your railing design calls for top and bottom rails, install the bottom rail ЗУ2 in. from the deck.

Carriage bolts are strong and attractive. The rounded head looks appealing, and the bolt provides excellent holding strength for major structural connections.

To make porch railings and stair handrails both safe and legal, you need to know the basic rules and regulations that dictate how they’re built. The specs here cover most areas of the country, but codes do vary from region to region, so always check with your local building department.

■ In most regions, any deck higher than 30 in. off the ground needs a railing.

■ Stairs with more than three risers (three steps) need a handrail.

■ Stairs that are 44 in. wide or more need a handrail on both sides.

■ The height of a handrail, measured from the nose (the front edge of the stair tread), should be between 32 in. and 36 in. The handrail should extend the length of the stairs.

■ The width of a handrail must be between 1 in. and 2 in. so that it’s easy to grab.

■ The railing height on a deck guardrail should be between 36 in. and 42 in.

■ The balusters used on porches and stairs should run vertically, so children can’t climb onthem. The spacing between them must be 4 in. or less, so children can’t squeeze through.

■

The bottom rail must not be more than 4 in. above the deck.

Posts, rails, and balusters must be precise. The clean lines on a finished porch or deck depend on accurate railing installation. Here, the posts are notched to fit against the rim joist. The ends of the decking boards overhang beyond the rim joist, even with posts.

[Photo © Larry Haun]

If you’re installing wood decking, keep in mind that many boards have a tendency to cup because of their circular grain structure. If you see a curve in the end grain of a board, lay it so the curve forms a hill rather than a valley. Should cupping occur sometime in the future, water will run off rather than pool. Exposed PT or cedar decking needs to be treated with a good deck finish every other year or so.

On narrow decks, the boards are often installed at a right angle to the house. I usually attach the first board on the end of the deck where the stairs are (or will be). Let the deck board overhang the end framing by about 1 in.

I cut the boards slightly longer than the deck. With the boards a bit long, you can snap a chalkline and cut them off evenly so everything looks neat and proper.

I use 16d nails as spacers between wood deck­ing boards. Placing one nail near the house and

another near the edge of the porch maintains consistent spacing. Where a board crosses a joist or beam, drive two decking screws. Those steel screws have a galvanized or polymer coating that protects against rust, and their coarse threads drive quickly and hold much better than nails do. To install l’T-in.-thick decking, use 3-in. screws. To install 5/4 boards, 21/2-in. screws will do. Although it takes a bit more time, I predrill the screw holes in the decking with a 3/i6-in.-dia. bit. This makes it easier to pull the boards tightly against the framing and just about eliminates the possibility of splitting a board.

When you reach about 6 ft. from the end beam, calculate how many more boards will be required to cover the distance, and check whether the distance is equal along the led­ger and along the rim joist. You may need to fine-tune the spacing between boards to restore parallel orientation and to make sure the final board is of a reasonable width.

Once all the deck boards are in place, snap a chalkline across the front edge about 1 in. from the rim joist, then cut them straight with a circular saw. Tack a lx to the deck to guide the saw and ensure a good-looking, straight cut. Take your time and do a good job. This is finish work, and it must look right.

STEP 6 INSTALL THE RAILINGS

Most codes require railings only when a deck is more than 30 in. off the ground, but you may want to build a rail on a lower deck anyway, for appearance if not for safety. The basic structure of a typical deck or porch railing consists of posts, rails, and balusters, which are also called uprights or pickets.

Even with basic PT lumber, many designs are possible. For example, you can eliminate the bottom rail, extend the balusters down, and fasten them to the rim joist. You can include a 2×6 “cap” installed over the tops of the posts and over the top rail. And you can use a chop – saw to bevel one or both ends of each baluster to give your work a sleeker appearance. There are even decorative PT balusters, along with shaped top and bottom rails that are grooved to hold baluster ends. Also available are quality vinyl railings that are attractive and maintenance-free. As I mentioned at the beginning of this chapter, it’s worthwhile to investigate the design possibili­ties, so take a drive around your neighborhood and visit a lumberyard or home center that car­ries these building supplies. No matter what the design, make sure the railing meets code require­ments (see the sidebar on the facing page).

TWO WAYS TO HANG STAIR STRINGERS

1. WITH METAL STRAPS 2. WITH A PLYWOOD HANGER BOARD

If you’ve done the stair layout and cutting cor­rectly, the stringers should fit against the rim joist (or beam), with the level cut or cleat for the top tread located 71/2 in. down from the top of the deck framing. Snap or mark a line at that level on the rim joist so you can make sure the stringers are aligned.

There are several ways to secure the string­ers to a deck beam or rim joist. Sometimes the stringer butts against a post, so it can simply be nailed to the post and to the beam or rim joist. In other situations, a metal strap can be nailed to the bottom of the stringer, then to the beam or rim joist (see the bottom photo on the facing page). Still another option is to fasten a PT ply­wood hanger board to the top plumb-cut edge of each stringer, then nail the board to the beam or rim joist (see the illustration on p. 190).

For a set of 36-in.-wide closed-stringer stairs, cut a hanger board 14 in. high and 39 in. wide, then nail it flush with the top of the deck’s

2×6 rim joist. Then measure down 71/2 in. from the top of the rim joist, mark the board on each end, and strike a line across it at that height. Drive 8d galvanized nails through the back of the hanger board and into the stringers below the 2x 6 rim, making sure the top of the upper cleats on both outboard stringers and the top notch on the interior stringers land on the line you snapped on the hanger board. To stiffen the top of the stairs, cut and install PT 2×4 block­ing between the stringers.

Next, cut a 36-in.-long PT 2×4 kicker board and nail it into the notch of the middle stringer and to the outside stringers. The kicker board can be fastened to the concrete landing or base with hardened nails, steel pins, or concrete anchors.