Ask The Experts
Porches, Decks, Stairs, Rails & Walks
We're expecting to have a large party soon, and I am worried about whether our deck will support a large group of people. What signs of trouble should I look for?
The potential for disaster is so great with an elevated attached deck, that we would have to recommend a professional inspection. Even if the deck was well built originally, it has been exposed to the weather for years, and the attachments and fasteners could have degraded in ways that may not be readily visible. Elevated decks should receive thorough inspections every few years, but here are a few tips that can help you generally assess the health of your deck. Look for any evidence of decaying wood, either of the framing and posts, or of the decking material that forms the floor. Poke at any possible soft spots with a screwdriver and replace all deteriorated wood. Any visible sagging or unevenness in the deck surface should be investigated. Check the method of attachment of the deck to the house. At minimum, you should find plenty of lags or bolts from the deck into the house wall and from the deck framing to the posts. Nails are not sufficient. If the deck is old enough that wood is decaying, the fasteners may be decaying also. A representative number should be removed and examined. Flashing, a metal barrier between the deck and the house wall should be visible from below the deck. The flashing is intended to keep water from entering the house wall or deteriorating the fasteners. Stand at the outer rail of the deck and rock back and forth. The deck should not move with you. Also, don't forget the rails. They should be solid feeling and not loose, and should be sufficiently high and closely spaced to ensure that no one takes a tumble over the rail or a child falls through the rail or becomes stuck. These are only rudimentary steps. If you are unsure, hire a professional to thoroughly inspect the deck.
I want to extend my older cantilevered rear deck, but my contractor insists on removing the existing deck, adding to the cost. Is there any good reason why it can't simply be extended?
Every year we read about decks that collapse, resulting in death or serious injury. The most common failure is detachment of the deck from the house. Decks should be built to the same structural standards as the floors inside the house. By code they should be designed to meet the same loads. They almost never are, even when built entirely new. Your contractor wants to be responsible for his work, but not for any problems that may be inherent in your existing deck. Building onto an existing deck is asking for trouble.
There are actually very good specific reasons why it is best to start over. First, a cantilevered deck is very hard to seal adequately at the house wall to prevent water seepage into the wall. Proper sealing, using metal pieces called flashings is critical to prevent decay of either the point of attachment of the deck or of the structural elements of the deck itself. Most older decks are decayed to some extent, even if this is not readily apparent. The wood may no longer be sufficiently strong to support the weight of an additional surface, and may not have been designed for the additional load in any case. The method of attachment of one deck to the other will have to be to some degree “jury-rigged”. Since such an attachment does not have a standard, the plans should be approved by a structural engineer, adding to your costs.
Every deck should be attached to the framing of the house wall using frequent lags or bolts. Nails alone are not sufficient. The deck should be attached directly to the structure of the house, not through sheathing or siding, for greater strength. Metal flashings should be installed from behind the siding over the top of the deck framing to force all water well away from the house wall to prevent decay. Full sized and properly fastened joist hangers should be used wherever joists do not bear directly on top of beams or ledgers. Guardrails should rise 36 inches above the deck surface, and no spaces at the rails and steps should allow the passage of a 4 inch sphere, in order to keep small children safe. We should take deck construction seriously. We need to keep our children safe, and a collapsed deck is a terrible way to end a party.
I am building a new deck and have been told that the new pressure treated lumber is corrosive to the nails. Are there special fasteners for the new decks?
Pressure treated lumber available since January of 2003 uses a different chemical formulation that no longer includes copper arsenate. The new lumber will be labeled as ACQ pressure treated. It is generally understood that the new formulation is significantly more corrosive, and that the standard galvanized fasteners and support devices that were previously suitable will not hold up. Usually, reputable dealers will stock the appropriate fasteners for the lumber they sell. To be sure that the fasteners are correct you should look for 185 or triple zinc coatings which are much heavier than the old standard. A common brand name for these products is Z-Max by Simpson. One of the problems we are seeing is that while deck screws and joist hangers have been upgraded, more corrosion resistant lag bolts to attach the deck framing to the house and posts, are not always being stocked. They should be hot dipped type. If you use nails, they should also be hot dipped galvanized. Deck screws are generally a much better fastening device and should be labeled for use with ACQ lumber. Another option, while expensive, is to use stainless steel fasteners. Make sure that you use appropriate joist hangers wherever the joists attach against headers and ledgers, use all the nail holes provided, and use the nails provided with the hangers. Also, don't forget to use a corrosion resistant flashing between the deck and the house. Traditional aluminum flashings will not hold up. Pressure treated lumber of either formulation should receive periodic resealing to help ensure that the wood itself does not dry out and deteriorate over time.
I have an older home with a nice wood framed front porch. I think it might be sinking though. How can I tell, since the floor is supposed to be sloped?
It would not be surprising if your porch is slowly dropping. Most of the porches built prior to 1950 were supported using small iron or wood posts bearing on minimal stone or concrete foundation piers, virtually resting on the surface of the ground. Poor surface water control from gutters and downspouts, and minimal bearing depth at the posts, will result in frost heave and settlement of the piers, or decay of the wood or steel posts where they are in soil contact.
You are right that porch floors are normally designed for drainage. The tongue and groove porch flooring is typically installed perpendicular to the front wall of the house with a one inch drop in height away from the house over the standard depth of a porch. You should be suspicious of any greater slope than this, but the easiest way to tell if settlement is occurring is to look at the box header. This is the beam above your head that bears the load of the roof and ceiling of the porch and is in turn supported by the porch posts. This should be level on the ends, between the house wall and the corner posts. If it drops toward the posts, your porch has settled. The next question is whether the settlement is ongoing. Since some portions of the porch will inevitably pull away from the house as the porch drops, you can look for fresh gaps between the roof, ceiling, porch rails, etc., and the house wall. If you know how long ago the most recent siding, porch windows, or trim were installed, you may be able to gauge the rate of movement. Once significant gaps have occurred, it is very hard to get the porch back where it belongs, so don't let things go too far. If repairs are warranted, make sure any new wood foundation posts are rated for ground contact, that sufficient bearing is provided at the bottom of the piers to support the load, and that the depth is adequate to ensure against frost heave.
What are the rules regarding handrails? I am building a deck with steps, and am getting conflicting guidelines from different sources.
An amazingly high percentage of home accidents involve steps, stairs, and handrails. Making sure that these areas are safe should be a high priority for all of us. It is unfortunate, but not surprising, that you are getting conflicting information. The rules have been changing recently.
In the last couple of years New York State has moved away from its own unique building code, known as Title 9, Executive (B), and adopted most of the provisions of the International Residential Code for one and two family dwellings. Codes do not remain static though, so future modifications in the code should be expected. But at present, there are a fairly clear cut set of rules that we can follow. A handrail is required at any set of steps with two rises or more. If moving from one level to another requires you to take two steps up, then a handrail should be installed. Handrails need to run continuously from the bottom step to the top step. They should be graspable, meaning something that you can get your hand around, based on its overall size or based on recesses in the sides that allow a good grip, and there should be adequate room for your fingers between the handrail and any wall. The required height above the steps for a handrail is 34-38 inches, measured directly above the nose of each tread.
All open sides of stairways and decks, landings etc. that are 30 inches or more above the adjacent floor or grade require guard rails. Guard rails need to be a minimum of 36 inches above the level they serve. The space between the rail top and the floor or stairs must not have any spaces that a 4 inch sphere can pass through, other than the triangular space formed at the ends of the treads and risers where 6 inches is allowed. The 4 inch rule applies between treads too, so open risers between steps are pretty much out.
Codes are in place to make our homes safer, and the details are important. When you are working on a project that requires a permit from local authorities, your code official should be your ultimate resource. In any case, the principle is also important. Steps and stairs are dangerous. Make sure that safe handrails and guardrails are in place, and that they are well secured.
The stairs to the 2nd floor in my house has been squeaky for a long time, but now I can feel some of the stair treads moving under my feet. What is the best approach to fixing them before I fall through?
Squeaky stairs can be mildly annoying, especially if you're trying to sneak through the house, but you are right to be concerned about your safety. Stairs really can deteriorate to the point where collapse is possible. Repairing squeaky or failing stairs is usually a fairly easy task, but before we discuss methods of repair, we need to make sure we are speaking the same language. The treads, of course, are the boards that you step on as you move up or down the stairs. The risers are the pieces of wood, set on edge, that fill in the spaces between the treads. The stringers are the long boards running from the top to the bottom on each side of the stairs which support the treads.
Loose stairs are almost always the result of inadequate fasteners, right from the initial construction. Whether you're building stairs, or repairing them, the key to success is to use lots of glue and screws. In most stair construction the sides of the stringers are routed out to create slots in the wood to accept the treads and risers. As the stairs are being built the treads and risers are slipped into the slots in the stringers from below or behind. Then hardwood shims are tapped into place in the slots on the back side of the treads and risers to tighten them against the top edges of the slots. These shims often loosen or fall out, allowing the treads to shift and drop. In addition to the attachment to the stringers, the front edge of each tread is fastened from the top face into the top edge of the riser below, and the riser is fastened to the back edge of the tread from behind. When these connections loosen, the stairs squeak.
Proper repair requires access to the underside of the stairs. If there is a ceiling in the way, it will have to be removed. It is best to start the repair process from the bottom, using new shims to push each tread into proper position, followed in turn by its corresponding riser, gluing and screwing each part to the other as you work your way to the top. Sometimes the stringers spread apart as a stairs loosens. You may have to draw the stringers closer together as you work your way up the stairs. When all of the treads and risers are tightly and thoroughly glued and screwed to each other and to the stringers, the stairs won't fail, and with a little luck they won't even squeak.