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By Steven Saarman

For both roofs and decks, semiannual inspections are the first step in any proactive preventative maintenance program. This allows the owner to identify and solve any problems as they occur with the least cost and consequential damage. The inspections should be scheduled in the spring, after the ravages of winter have passed, and again in early fall, after the heat of summer has passed and in anticipation of winter. These are critical periods to “tune up” both systems. Both roofs and decks are basically horizontal surfaces and, consequently, get more abuse from the elements (like sun and rain) than any other part of the building.

Roofing Maintenance Checklist
The most common roofing materials used locally are: asphalt composition shingles, built-up and modified bitumen, wood shakes and shingles, and clay or concrete tiles. There are maintenance elements common to each of these roof types, as well as type-specific maintenance procedures.

For all roof types, start out your maintenance routine by cleaning all debris from the roof surface. This includes debris that has accumulated behind HVAC units, skylights, chimneys, pipes, pitch pockets or any other penetrations. Debris has a tendency to retain moisture and accelerate the deterioration of the roofing material, especially if it is asphalt or wood based.

Check all flashings to make sure they have not deteriorated, there are no holes in them or that joints or seams have not broken loose due to thermal expansion and contraction. If flashings need to be replaced, always have flashings installed with “slope to drain” away from the building, not flat or reversed sloped, which will pond water, thereby holding seams and joints under water and increasing the potential for leaks.

Check all caulking and sealants on flashings, caps or copings. Scrape and remove any caulking that is cracked and damaged. Thoroughly clean the surface of any old caulk and paint. Replace the old sealant with a new high-performance polyurethane caulking such as NP-1 or SIKA – FLEX IA. In general, when replacing any sheet metal, always solvent clean the surface (using Acetone, for example) to remove the residual oil left on the surface from the galvanizing process prior to caulking or painting.

Keep your gutters and downspouts, drains and scuppers clean and free of debris. Test your downspouts before winter to make sure they run free and aren’t clogged. Clogged downspouts cause gutters to fill up in heavy rains and increase the chances of water flowing backwards under the roofing and roof flashings. Trim back any overhanging tree branches that will add to accumulated roof debris and possible abrasion to the roof surface during windy conditions. This is also a good idea from a fire prevention point of view.

If you have a split-level roof, make sure the siding around the roofing is maintained. This siding is often not looked at, so it has a tendency to fall into disrepair. These side wall leaks are often interpreted as roofing leaks. Keep moss, fungus and algae off your roofs. As the organisms grow, they penetrate the wood or asphaltic surfaces, breaking down the wood, weakening fibers, wearing off the protective granules or coatings, and generally accelerating substrate deterioration. “Zinc control strips” along ridges and hips are an effective and proactive control measure and are easy to install.

With asphalt-composition shingle roofs, replace any weather-damaged shingles (such as those that are cracked, curled or missing). As a tune-up, if some of the shingle tabs are loose, apply a dab of roof cement on either side of the tab to reattach. This will help prevent wind “blow off.” Remember, a shingle roof is a waterproof plane composed of overlapping layers of shingles like the feathers on the back of a duck. When healthy and well maintained, water will always run off.

Built-up or modified bitumen roofs consist of multiple layers of “felts” (asphalt-impregnated sheets) laminated together with bitumen and designed for a low slope. Low-sloped roofs are generally sloped a minimum of a quarter-inch per foot for drainage, while sloped roofs generally have a minimum pitch of four inches per foot. Proper substrate sloping with valleys and crickets allow water to be channeled toward drains and avoid ponding. Therefore, the condition of the surface is critical. Water ponding over 48 hours accelerates roof deterioration and creates a “reservoir” when a leak occurs.

Gravel is applied and imbedded into the top asphalt surface to protect the lower layers from UV penetration and material breakdown. This is why bald spots need to be addressed immediately. Also, check the edge metal nosing around the perimeter of the roof. Make sure it isn’t separating at the seams where the asphalt overlaps onto the metal. If you detect blisters in the roof, don’t step on or puncture them.

Blisters are a sign that moisture has entered between the roofing layers and the warmth of the sun has caused the water to vaporize and expand between the layers, creating the blister. Contact a qualified roofing contractor to repair any of these issues if noticed during one of your semiannual inspections.

As a reference point on the life span one can expect from a built-up roof, under ideal conditions, a 3-ply built-up roof should last at least 15 years, a 4-ply should last at least 20 years and a 5-ply should last at least 25 years. Quality installation and proactive maintenance is the key to achieving the full life expectancy of any roof system.

Cedar shakes and shingles have been used for hundreds of years because they perform well. Cedar is a wood product, so it needs to breathe and, therefore, the surface (meaning both the top surface area and the keyways between the shingles) must be kept clean of debris. Attic ventilation is also very important with cedar shakes or shingles, so heat and moisture do not build up in the attic area and detrimentally affect the life expectancy of the shingles.

Clay and cement tiles are extremely durable, fire resistant and long lasting. If being considered as a roof replacement alternative, the roof framing must be analyzed by a structural engineer because of the added weight of the material. After the semiannual inspection, the roofer should replace any cracked tiles, tune up any flashings, and repoint ridges and hips with mortar to maintain a watertight condition.

For older color-faded roof tiles, new waterproof roof coatings are now on the market. They provide a “fresh” look with the potential of a color change to the tile and can incorporate solar reflective pigments, which will dramatically minimize heat gain in the building.

Deck Maintenance
Decks are built to provide an exterior extension to the interior living space.
As an extension, it therefore has a structure for support, a means of attachment
to the building and a walking surface. Each of these areas has design and maintenance concerns.

What the deck structure is made of is determined by design and building codes. Wood-framed deck structures are built from either Douglas fir framing or pressure-treated framing material. If the deck surface is of a membrane type that moves water horizontally and does not allow water to pass through and soak the framing, the framing material is generally made of nonpressure-treated wood. If the walking surface is open slotted planking where water drains through the surface and wets the framing, by code, pressure-treated material must be used. Under normal exposed conditions, pressure-treated lumber will mini
mally last two to three times longer than nonpressure-treated lumber.

There are deck-type specific flashing details for both membrane and open drainage deck systems. Membrane-type decks are like roofs and must be constructed to be watertight. Water only touches the top walking surface, so the waterproofing elements and flashings work together to form a “bath tub” with a drain. With an open drainage deck system, water runs through spaced decking and over the supporting wood structure, the structural metal fasteners, nails and bolts which then become susceptible to decay and corrosion. When the structural framing material is pressure treated, wood decay is not an issue, but there is a heightened concern with corrosion of the metal fasteners. Standard carbon steel or aluminum should never be in contact with pressure-treated material. Even electroplated nails or fasteners do not have a thick enough layer of
zinc to provide adequate corrosion protection. Only hot-dipped galvanized or stainless steel nails, screws, bolts and fasteners are recommended.

The traditional surface walking material for open drainage decks has been All-Heart redwood, which has a service life of 10 to 20 years. Alternate wood products, such as mahogany and ipe, have become popular due to the increase in cost and scarcity of All-Heart redwood. Ipe is a hardwood requiring moderate maintenance and has a service life of at least 20-plus years. Redwood with sapwood (white in color) is inferior for decking because sapwood has little decay resistance and will only provide a service life of 7 to 12 years, but it is cheaper.

Manufactured composite decking materials are also a viable option. They come in various colors and profiles, will not rot, have very low maintenance requirements and generally come with a 10-year warranty, but are expected to last 30 to 40 years. When choosing a replacement decking material, consider the cost of material, anticipated service life, maintenance requirements, slickness of the surface when wet and flame spread characteristics.

Combustibility of decking materials, both real wood and composite materials, was tested because decks are often a path of egress during a fire. The decking material that maintained the greatest structural support and also had the lowest flame spread characteristics was redwood! If your deck faces open space, this should be a consideration.

Another issue with open drainage decks is the attachment of the deck boards to the framing. Over time, nails that attach the deck boards will channel water down into the center of the structural framing members and cause decay. That is why the building code now requires all exposed deck framing to be pressure treated. If replacing decking over existing nonpressure-treated material, protect the top of the joists with a strip of flexible self-adhering membrane, which self-seals around the penetrating nails and helps prevent water from being channeled into the center of the framing. Simpson Hardware also makes metal fastening strips, which allow attachment below the deck surface to both the side of the joist and into the bottom of the deck board, thereby alleviating the need for top nail attachment.

There are two types of membranes used in decks: buried and surface applied. Buried-membrane decks consist of a waterproof membrane integrated with metal flashings installed over a sloped substrate. The membrane is covered with a drainage/protection mat to facilitate movement of water over the top of the membrane and to protect the membrane for the next step. This membrane system is then overplayed with concrete or mortar and tile as the primary wear surface, fully protecting the waterproof membrane below. This is the most costly deck system to initially install, but offers the tremendous advantages of very low maintenance and a service life of 50-plus years. Only poor installation details or application will cause this type of deck to experience problems.

Surface-membrane decks are very popular, have much lower installation costs and require moderate maintenance. On average, they must be top-coated every 3 to 5 years and a new membrane must be applied every 12 to 15 years. They are damaged by prolonged moisture and are prone to abrasive damage (like unprotected furniture feet, heavy foot traffic, etc.). Repairs are easily executed and affordable, but, if left unattended, substantial damage may occur to the supporting surface and structure, escalating repair costs.

Typical preventative maintenance programs for surface membranes involve visually inspecting each deck semi-annually. Because the top surface is the waterproofing element, its condition is critical for performance. Just like a preventative program with roofs, remove all debris from accumulating and trapping moisture. Make sure nothing is placed on top of the membrane that is stopping it from drying out. Visually check seams, look for cracks, note water stains indicating ponding and look at heavily used areas, such as below a table or barbeque, for problems with the membrane surface. Make sure drains and scuppers drain freely. Lightly power wash the surface to remove moss, fungus or algae. A mild soap or TSP solution may be used to help clean the surface and remove stains.

To get the most out of roofs and decks, develop and implement a preventative maintenance program to achieve full life expectancy of each system. An observant eye and not “living in denial” by deferring maintenance, is a large proactive step forward. If you are at the stage to consider replacement of materials, become a vigilant and well-informed consumer. Utilize the resources around you and ask questions. As is often said, “The only dumb question is the question not asked.” You are ultimately the guardian of your own equity and the destiny of your building.

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The opinions expressed in this article are those of the authors and do not necessarily reflect the viewpoint of SFAA or SF Apartment Magazine. Steven Saarman is the president of Saarman Construction, Ltd. Copyright © 2008 by SF Apartment Magazine. All rights reserved.