When it comes to the roof of your home, the rule of thumb is to "walk on its surface as little as possible"
The use of a pressure washing on a shingle roof, "can ruin your roofing". Any pressure over 300 Psi can lift your roofing and thereby destroy it.
Discoloration of your roof by algae is common throughout most of the United States, being most prevalent in the southeastern and northwest parts of the country. The build-up of algae expedites the deterioration of roofing materials. Roofs darkened by algae will absorb the sun's rays, which can heat the interior and raise your energy cost.
There are two methods to solve the algae problem. For those will shingles can utilize a zinc strip at the roof ridge, one placed on each side of the ridge., when it rains the runs off from the zinc strip will flow down the roof, eventually cleaning off the algae. The other method is directed at those with metal roofs. On these, it is necessary to manually (brush) apply an application of bleach, soap and water to eliminate the algae; You will have to be diligent in this, as it will require a few applications. After a section about ten feet square is done, you will hose off the residue.
Note: It is wise to hire a professional to perform this cleaning.
If your roof leaks, it can be very difficult to chase down the source of the leak, as they can be quite evasive.
When trying to locate a leak, use the following guidelines to assist you. Laying out a 10-foot square grid on your roof, which really helps, walk off this grid and look closely for signs of source of the leak. Bear in mind that it is really difficult to eliminate a leak while it is raining and unfortunately, you will most likely not be able to get a contractor to come out immediately.
Before you begin your search for th
e leak on your rook, ask yourself, has anyone been on your roof doing work? an electrical contractor, HVAC mechanic or anyone else? if so, were they anywhere near the leak area? It will help in your narrowing down the source of the leak. On occasion, plumbers, electricians and others working in attic, can accidentally knock loose flashing or possibly break loose a seam along a condensing line, or even punch a hole in the roof.
If this is not the case, then follow these tips:
For Low profile roofs:
-Inspect any roof drains near the leak area. If they are plugged or draining slowly, then there is a good change that they are the culprit. If so, clean out the debris, and if necessary flush down with water.
-Inspect any material seams in the area of the leak. Using a flat blade, gently run it along beneath the lap. If it slides in more than an inch, then the seam should be sealed. If it slides in for the length of a 2 inch blade, it’s a candidate for a leak.
-Look for holes in flashing, deteriorated caulking, curled flashing flanges that are sticking up through the roof, or any other visible defects.
-Look for blisters that have been punctured.
-If a leak occurs near the edge of the roof, check the edge metal, it can separate at the seams and tear the roof membrane in the process
-Check under piles of debris, often it has been sitting for a long time, then it can hold water which will speed up roof deterioration, especially that of shake. Occasionally you will find rodents and other vermin nest under these piles of debris.
-If in the end you find nothing that would preclude a leak on the roof, then it is time to check your attic or ceiling space. Occasionally what is mistaken for a roof leak, can be a problem with your plumbing in the attic.
-Another question, has any mechanical contractor been in the attic?
-Lastly, is the drain pain under your heating /cooling unit leaking? The unit might be leaking. Normally there is a drain fitting at the bottom of the pan, allowing evaporate to flow down a pipe to the outside.
For Steep Roofs:
-Look closely at all roof penetrations in the leak area, you’re looking for holes or damage.
-Look for nail heads. Nails that are not covered by the following course of roofing material. If the nails are exposed too long, sometimes they will rust, leaving a hole and causing leaks.
-Take a look at the mortar on the chimney, it is rare that it is damaged, but sometimes it happens.
-Check that all drains are functioning and your gutter is not full of debris. Sometimes when your roofing is installed and the edge details (overhang) and gutter details are not done correctly, water can back up over the top of the facia, run along the soffit, and down the side of the wall, the path of least resistance.
-Another item to look carefully is your roof mounted HVAC unit. Sometimes they can have a faulty pan, which will permit water to enter the house during a storm.
-Finally, look for piles of debris that can block water flow off the roof, sometimes this will cause the water to back up under the roofing itself. Look carefully behind chimneys and in the valleys of the roofing.
Leaks can travel a long way, so don't assume that the source is directly above.