Ask The Experts

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.

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.

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.

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.

A cross-connection is any arrangement in the plumbing system where waste water is potentially connected to the potable water supply, your drinking water. This can happen in any number of ways. In your case, we suspect that the tub spout is located within the body of the tub. If you were to fill the tub with water, the spout would be under the water. If the water pressure from the street, or in the house, were to drop significantly, bath water from the tub could be drawn into the water pipes, contaminating your water supply, and maybe even your neighbor’s water. That possibility is the primary reason why we get a “boil water advisory” when a major break or pressure drop has occurred in the municipal water supply. Look around at your other tubs and sinks. You should see that all of the other spouts are above the rim of the tub or bowl, where they cannot become immersed in waste water.

Sometimes cross-connections occur because of our specific actions. For example, if you were to leave a hose lying in the kiddie pool while you were filling it, a drop in water pressure could suck the pool water into your water supply. Other instances of potential cross-connection include dishwashers, washing machines, and water softeners. Most of these devices, if properly designed and installed, won’t allow contamination of the water supply to occur.

Plumbing codes often require that a backflow preventer be installed on the water service into the house. This device prevents supply water in the house from flowing back into the municipal supply. But, most older homes and many new ones don’t have these devices installed, and even if you had one, your own water could still be contaminated by a cross connection if your water pressure was poor. Replacing the tub is a good idea.

By the way, you will probably notice that your tub doesn’t have an overflow drain. If you’re drawn away from the tub while you’re filling it, you may end up with more than a cross-connection. You could end up with a minor flood.