Roof maintenance and repair can be a frustrating experience compared to repairing and maintaining your automobile.  If you discover a minor squeak or vibration in your car and take it to a mechanic, it might turn out to be a major problem.  Then, to add insult to injury, after you get your car back ad swallow the expense, you still have the squeak or vibration.

Repairing roof deficiencies provides the same results or lack of results.  What went wrong?  You had a problem with your car and took it to a mechanic for repair.  The mechanic diagnosed the problem and performed a wrong or improper repair.  You paid a cost that provided no benefit.  Similarly, when a minor blister on the roof requires repair, you can call the roofer to patch it.  You get the bill and find that the repair cost you several thousand dollars.  During the next rain the roof leaks at the area of repair where it had never leaked before.  Sound familiar?

Are you spending money on your roof and do not know what this money is buying?  Does it appear there is no end to leaks or bills from your roofing contractor?  Perhaps it is time to manage your roofs, instead of allowing them to manage you.   A successful roof maintenance program consists of four elements:

• a commitment from management to support and fund the maintenance program,
• an assessment of roof conditions to determine the most cost-effective repair,
• accurate identification of roof deficiencies, and
• proper repair of the deficiencies.

In many instances, the level of management commitment to a maintenance program is nothing more than a grudging willingness to repair any leaks that occur.  Unfortunately his level of commitment leads to premature roof failure.  Once leakage occurs, the roof system has already suffered internal damage.  The goal of an effective maintenance program is to extend the life of a roof system to its maximum potential.  As with a ca, if you want it to last, you don't wait until the little red light starts glowing to change the oil.

Unless your building is new, you need a roof condition assessment to determine the level of maintenance required.  The most effective dollars are spent on roofs that are in good condition now.  It is not cost-effective to spend one or two dollars per square foot to repair a roof that will be replaced in 2 to 3 years.  Roofs in a prefailure condition require a level of repair different from that on a roof with many years of service life remaining.  

Identifying roof deficiencies before they become leak conditions is key to successful maintenance.  Give the roof repair technician proper direction.  The technician you send to repair the leak as well as "everything else that's wrong" does not have in mind the same goals as your maintenance program.

Identify the deficiencies as part of an independent inspection, unrelated to the physical repair of the roof.  Whether you, your roof contractor, or an outside consultant complete this inspection, the inspector must be aware of your goals as well as the roof condition.  During the inspection, mark with spray paint the deficiencies as they are located (if the roof is highly visible, you may not want deficiencies marked).  Then, mark the location of deficiencies on a roof plan.  This helps the repair technician identify the areas where repairs are needed.

After identifying the deficiencies, determine an appropriate level of repair for each deficiency and roof condition.  Take into consideration the maintenance program goals.  Determine which roofs are worth aggressive action and which are worthy only enough investment to stop leakage.

Determine how the repairs are to be contracted.  In many instances, repairs are performed on a time and material basis.  Identifying the repairs gives the technician an idea of the extent and scope of the work.  Give the technician the required standard of quality if you want to obtain bids for the work.  If you do not want to bid work, your contractor can provide a time and materials not to exceed price.  The repair requirements should be specific enough that the technician completing the repairs will have no question as to what is required for the repair of each deficient.

Common roof repair items
Partially blocked drains or missing drain strainers.  Clean the drain strainer and rod out the drain, if needed.  Install cast iron strainers where missing.  Plastic strainers tend to blow away if they become loose.

Pitch pans low on filler.  If water stands in the pitch pan or if the filler is cracked and pulled away from the sides of the pan, fill the gaps with a pourable sealer.  Do not use plastic roof cement as it will eventually dry and crack.

Dirt and debris trapped in the valleys or in corners of the roof.  Debris tends to trap water that promotes algae growth and accelerates the breakdown of both built-up and single-ply roofs.  Remove debris from the roof.  Power washing the roof may be required for cases of accumulated dirt.  This is particularly true if coating is to be applied to the roof.

Open perimeter or base flashing laps.  An open lap in the flashing may be quite obvious, or it may require probing to check the integrity of the lap.  The typical flashing is open at the transition from horizontal to vertical.  Roof cement does not adhere to vertical surfaces and will soon slip off the lap.  Use the appropriate adhesive or heat weld single-ply flashings.  Repair built-up or modified flashing with a flashing cement.

Slipping or sagging flashings.  If the slipping or sagging of the flashings is severe, determine if the damage is a sign of a more serious condition.  In minor cases the flashing may be renailed at the top.  In a case of serious sagging and wrinkling, the flashing will have to be replaced.  Flashings on single-ply roofs are sometimes pulled towards the center of the roof creating a bridged condition.  In this state the flashings can be cut at the base and a new flashing placed over the top.  Be careful if this condition exists.  One must be sure the field of the roof is in stable enough condition that the repair will be effective.

Displaced metal.  Loose metal is subject to further wind damage.  Resecure loose metal using neoprene grommeted fasteners.  Check the caulking on reglet joints for cracking and shrinkage.  If the caulking needs to be replaced, remove it and apply a high-quality butyl caulk.

Built-up systems
The key to repairing a built-up or modified system is surface preparation.  Any gravel must be spudded or removed to expose the top plies of the felts.  Apply an asphalt primer to the felts to ensure that the repair properly bonds to the existing surface.  If the system is smooth surfaced--or tumen--verify that the surface is clean before applying primer.

Holes or punctures in the filed flashings.  Physical damage in the field and flashings usually occurs in high traffic areas around HVAC units and in the traffic areas leading to the units.  Provide ramps at expansion and control joints so that equipment may be taken over the joints without lifting.

Repair damage to the field or flashings in a built-up system with something other than roof cement.  An atactic polypropylene modified bitumen works well for long-term repairs and avoids having to set up a kettle to complete the repair.  Atactic polypropylenes are applied using a torch and open flame.  If this poses a problem at your facility, then you must use hot asphalt and felt pipes.

Blisters in the field.  Though unsightly, blisters do not, in themselves, pose a threat of leakage unless they are ruptured or punctured.  Repair blisters only if the gravel sloughed off the tops to expose the felts or it they are in a high traffic area.  To repair a blister, cut an X pattern in the blister or remove the blister to leave a flat surface.  Use the same repair method as if damage were in the field.  Restricting foot traffic helps avoid inadvertent damage.  Extensive blistering is a sign of a greater problem usually related to the original roof system installation.  The only cost-effective correction for extensive blistering is replacing the roof system.

Ridges.  A ridge appears as a sharp crease in the field.  Ridges in the field of the roof are usually the sign of poor insulation attachment that allows unrestrained roof system movement.  Unfortunately, if not properly repaired, creases eventually split, usually in the middle of winter.

A long term repair is possible for isolated and random ridges.  To repair the ridge, spud the gravel out at least 18 inches on each side.  Cut the ridge so that it lays flat.  Prime the area with asphalt primer and lay a dry felt extending a minimum of 6 inches on each side of the cut.