Home Inspection FYI

Providing Help, Knowledge and Other Useful Information To Home Owners Everywhere

Home Inspection FYI - Providing Help, Knowledge and Other Useful Information To Home Owners Everywhere

Roof Shingle Inspection and Individual Replacement

Shingle inspections can usually uncover a problem and can in most cases be replaced by breaking or cutting their adhesive-strip bonds. Once the fasteners are removed, the damaged shingle can be replaced with one that matches, and then hand-sealed.

Removing a damaged shingle without damaging the surrounding shingles may be impossible on older roofs with brittle shingles. If this appears to be the case, be sure to have an extra shingle or two available or seek the help of a professional roofer.

It’s also sometimes possible to perform spot repairs. For instance, if granules are missing in a few places from something such as a blister pop, it’s possible to add roof mastic and sprinkle on granules, but this type of repair is not common.

Performing a Shingle Inspection

The asphalt shingle inspection actually starts on the ground.  Walk the home’s perimeter, and look in the yard for shingles or parts of a shingle that may have come off the roof.  If you find any, it’s likely that they’ve been blown off.  But, occasionally, they can find other ways of making it down to the ground.

If you find a shingle on the ground, you should look for missing shingles on the roof and check to see which components failed, why they failed, and the extent of the failure. Is the damage limited to a few shingles?  Have shingles on the whole roof failed in the same manner?  Or, is the failure limited to certain areas?

You can sometimes tell by looking at the shingle or shingles you find on the ground what you’re likely to find on the roof. For example, if you look closely at this shingle (pictured below), you can see that it was fastened with staples. The missing sections along the top are where this shingle tore loose from the staples that fastened the shingle in the course above.

improperly installed staples shingle 300x194 Roof Shingle Inspection and Individual Replacement

If you look closely, you can see the marks left by the staples that held this shingle in place. The crowns of the staples should have been parallel to the length of the shingle but, as you can see, the installer rotated the staple gun as he fired, installing the staples at both ends at an improper angle. Once you climb onto the roof, you can expect to find shingles that were fastened with poorly installed staples.

shingle pullover Roof Shingle Inspection and Individual Replacement

You can see that this shingle was fastened with nails that pulled through. The upper hole in this shingle was made by a nail that was hidden by the shingle in the course above.

The lower hole was made by a nail that was added after the roofing was installed and would have been visible. This is often a sign that the shingles are poorly bonded and needed additional fasteners to avoid losing shingles to blow-off. In this case, you’d want to be diligent in checking shingle bonding on the various roof slopes.

Looking On the Roof

Once you’re on the roof, walk each slope. You should start at the bottom and work your way up the roof, just to make sure that what you find hasn’t been caused by you. This is a possibility on older roofs with fragile shingles, and on new roofs with shingles which haven’t really had time to cure. Newly installed shingles can still be soft enough to damage easily, especially on hot days.

Checking Shingle Bonding

As you work, tug lightly at shingles in different areas to check the quality of the adhesive-strip bonding. Be sure to check areas subject to greater uplift, such as corners, rakes, just above the eaves, and on the downwind side of the ridge.

If shingle bonding is marginal, you don’t want to break the bond and give the wind the chance it’s been waiting for to start stripping shingles off the roof.

Pay attention to shingles that may have been shaded. They may be on a slope facing a direction that gets very little sun, or parts of the roof may be shaded by trees or mountain ridges, or other parts of the roof.

Also, pay attention to slopes that face the direction from which the prevailing winds blow. These slopes are the most likely areas to have suffered contamination from debris.

Shingle Fastening

If you find tabs on a shingle that lift easily make note. Tabs that lift easily are not a good thing, but this will allow you to be able to see the fastener type and placement.

It’s a good idea to avoid breaking any adhesive bonds at all.  But if you do, mark those shingles with chalk and, before you leave, hand-seal them using a caulking gun and roof cement.

If you find areas with missing shingles, pay attention to the fastener installation. If it’s incorrect, the problem may not be limited to that area.

If you find shingles on the ground, you can reconstruct the failure, assuming it was wind-related. This may help you to determine the potential for further damage.

1.  First, the adhesive bond failed, allowing tabs to lift, stressing them and putting additional stress on the shingles beneath the fasteners.
2.  Either the fasteners held the shingle in place, in which case you might expect to see creasing or tearing of the tab, or the shingle pulled over the fastener, indicating that the fasteners may not have been installed correctly.

3.  When shingle tabs bend or flex excessively, the adhesive strip of the shingles in the course above or to the sides may be affected. Check the shingles near the damaged areas to determine the full extent of the damage.

Shingle Problems

Continue to walk each slope until you’ve covered the entire roof. In addition to shingle bond and fastening, you should check for any problems related to the shingles’ manufacture, installation, appearance and design, and damage or deterioration from environmental or mechanical sources.

roof gauge Roof Shingle Inspection and Individual Replacement

You can document the roof pitch accurately by checking it with a roof gauge.

shingle gauge Roof Shingle Inspection and Individual Replacement

Using a shingle gauge to check shingle thickness will give you a good idea of the length of the warranty.

Check to see how many layers are installed, and note if more than one layer exists. If underlying layers are of a different roof-covering material, that information should also be remembered

roof edge gauges Roof Shingle Inspection and Individual Replacement

You can record all three conditions in one photo if you use the shingle and pitch gauges at the roof edge. You can also show whether edge metal is installed.

Flashing Problems

Check the roof for the proper installation and the condition of the flashing. You may need to look at the roof edges to see flashing that may be mostly hidden by shingles.

Underlayment Problems

If possible, confirm that the underlayment was properly installed.  Underlayment should be visible only at the roof edges. Your main concern is a roof with a pitch of less than 4:12.  The underlayment should be installed in such a way that it’s doubled under the entire roof.  If you discover any exposed underlayment, address the problem as soon as possible.

Roofing Underlayment

Underlayment and their different properties.

When a roofer first walks onto a job, unless he’s tearing off an old roof-covering material, he’s faced with a bare roof deck. After the edge metal on the eaves, the first component to be installed on the roof is underlayment.

Underlayments are manufactured with different properties designed to meet the needs of homes in different climate zones. An underlayment that works well under metal roofing in a hot, humid place such as New Orleans, Louisiana, may not work well beneath wood shakes in a cold, dry climate such as Jackson, Wyoming.

The different types of roof-covering materials may have specific underlayment requirements. You will not be responsible for confirming that the proper type of underlayment was used, but if you see problems with the roof, understanding the basic properties and general installation requirements of underlayment may give you clues as to the source of the problem.

Although underlayment is typically required by building codes in new construction, in the past, roof-covering material manufacturers haven’t always required it.

The PURPOSES of UNDERLAYMENT

Moisture Barrier

Most roof-covering materials are not waterproof, but they are water-resistant, and are designed to be installed over a waterproof or water-resistant membrane of some type. “Underlayment” is the general term used to describe these membranes.

Even though underlayments are the first materials to be installed on the roof deck, the roof-covering material — the shingles, tiles, metal or slate – makes up the primary barrier against roof leakage. Underlayment is a secondary barrier.

Water-resistant underlayment may allow the passage of moisture vapor but prevent the passage of water in its liquid form.

Waterproof underlayment will prevent the passage of both liquid water and water vapor.

 1 7 1 underlayment Roofing Underlayment

Waterproof underlayment is typically used on parts of the roof that are more likely to leak or suffer moisture intrusion. This includes penetrations, areas where roof-covering materials change or end, and low-slope sections of the roof. It’s not unusual to use combinations of underlayment on a home’s roof.

The “permeability” of underlayment is the extent to which it allows the passage of water vapor. Although all underlayments are designed to prevent the passage of moisture in its liquid form, they can have different levels of resistance to the passage of water vapor.

Underlayment permeability ratings are provided by the manufacturers and are less important in roof underlayment than they are in house-wrap. Underlayments with a perm rating of 1 or less are moisture barriers. Underlayments rated above 1 are moisture retarders.

Temporary Protection

 1 7 2 Roofing Underlayment

Underlayment provides temporary protection of the building interior and the roof deck before the roof-covering material is installed.

In a perfect world, the roof-covering material would be installed as soon as possible.  But in the real world, the roof may be protected by underlayment alone for days, weeks and, sometimes, months.

Protecting the building interior is especially important when an old roof-covering material is being replaced and the home interior is finished.

During that time, the underlayment may be under attack from weather elements, such as high winds, UV radiation and precipitation.

It also needs to resist the wear and tear that occur when the roof-covering material is being installed.

Preventing Chemical Degradation

Underlayment also provides a layer of separation between roof sheathing and the roof-covering material.

Newer homes use plywood or an engineered panel called oriented strand board (OSB) for roof sheathing.

For many years, pine or fir boards were used as sheathing, and many older homes still have these boards in place.

Resin pockets in these boards can react chemically with some roof-covering materials, such as asphalt shingles. In these situations, missing underlayment can cause accelerated deterioration and premature failure of the roof-covering material.

Fire Resistance

Underlayment materials are available for wood roofs which increase their resistance to fire. In fact, without special underlayment, wood shakes and shingles cannot achieve a Class A fire rating, which is the highest available.

 

Underlayment Information Right Here

More About Housing and The Construction Industry

Asphalt Composition Shingle Thickness

Checking Asphalt Composition Shingle Thickness

 

FIELD-CHECKING SHINGLE THICKNESS

The quality of asphalt shingles is generally reflected in the length of the warranty. You can get a good idea of the length of the warranty of strip shingles by checking the shingle thickness using a shingle gauge.Shingle gauge 3 tab11 300x169 Asphalt Composition Shingle Thickness

This device has a tapered slot lined with calibration marks that show the warranty connected with the shingles thickness. You won’t be able to positively identify the warranty of the roof, but using the gauge allows you to get a good estimate.

Shingle gauge 3 tab2 300x169 Asphalt Composition Shingle Thickness

Here’s how you use it on a three-tab shingle.

When you use the gauge on laminated shingles, you need to use it on a portion that’s only one layer thick. Shingle gauges are less accurate on laminated shingles.

Checking the shingle is fast and easy, and allows you with valuable information at little cost to yourself.

Understand that you are not certifying the roof or confirming a warranty on the roof, or implying that it’s covered by a warranty. That by measuring the thickness of the shingle will identify the approximate length of the warranty, but does not accurately reflect the length of its expected service life.

A warranty for shingles is a marketing tool, since the warranty seldom reflects the shingle’s actual lifespan. A warranty offers a way to roughly compare the expected service life of different asphalt shingles.

Shingles may have one warranty, two warranties, or no warranty at all.

A warranty may transfer once with the sale of the home, or it may transfer as a limited warranty, or it may transfer fully.