Before You Make an Offer, Part 3
What to Look for on the Roof During a
Home Showing.
You do not need a home inspector to walk a showing. You do need to know what to look at. Five minutes on the outside of a home, looking up, can tell you a lot about what you might be agreeing to buy.
How to Use This Guide
This is not a home inspection. It is a framework for your showing. Use it to observe, note, and question. The goal is to walk away with a clearer sense of what to hand to your inspector as a specific list of concerns. Nothing in this guide replaces a professional evaluation from a licensed home inspector.
Area 01
The Roof Plane: Start at the Street
What to do
Step back to the street or the far edge of the driveway so you can see the full slope of each roof plane. Look at the ridge line first, then scan down each slope to the eaves. Do this on all sides of the house you can access.
Most roof problems are visible at this distance if you know what you are looking for. You are scanning for shape, uniformity, and surface condition. A roof should look flat and consistent. Anything that interrupts that is worth noting.
- The ridge line dips or sags in the middle. This indicates the ridge board has shifted, the supporting structure underneath has moved, or the decking is failing. It is not a cosmetic issue. It needs evaluation before you move forward. Look more carefully
- One section of the roof plane dips or wavers. A flat plane that suddenly dips in one spot usually means the sheathing underneath is deteriorating. This often comes from a slow leak that has been rotting the decking from below. The shingles on top may look intact. Look more carefully
- The shingle color varies noticeably in one section. This often means a section was replaced at some point, likely after a leak or storm damage. A patch repair is not necessarily a problem, but it raises the question of what caused the damage and whether it was fixed correctly. Worth noting
- You can count multiple roof layers from the edge. Building code allows a new layer of asphalt shingles over no more than one existing layer, so two layers is the limit. If you can see two or more layers at the eave edge, the next replacement will require a full tear-off, which is significantly more expensive. Ask your inspector to confirm the layer count. Ask your inspector
Area 02
Shingle Condition: What the Surface Tells You
What to do
Look at the shingles on the slopes you can see clearly. You are looking at the edges of individual shingles, the overall color uniformity, and any shingles that are obviously missing or displaced. Bring binoculars if you have them.
- Shingle edges are curling upward at the corners. This is called cupping or curling, and it is a sign of age or moisture damage. Shingles in this condition are more vulnerable to wind uplift and no longer seal flat against the decking. The roof may be in its final years. Look more carefully
- Individual shingles are visibly missing. One or two missing shingles after a windstorm can be patched. A pattern of missing shingles across a slope points to fastener failure or shingles at end of life. Either way, those areas are exposed to rain right now. Look more carefully
- The shingles look dark, worn, and granule-bare from a distance. Asphalt shingles lose their surface granules as they age. Heavy granule loss means the protective layer is gone and the underlying fiberglass mat is exposed to UV and water. This roof may be at or near the end of its rated life. Ask for the replacement date and discuss it with your agent. Ask your inspector
- There are visible cracks or broken shingles in one area. Impact damage from hail or falling branches can crack shingles without displacing them. The shingle looks intact from a distance but has a split that lets water under it. Not always visible without binoculars. Worth noting
Area 03
Moss and Debris: Portland’s Permanent Houseguest
What to do
Look at the whole roof surface. You are looking for green growth, any lifted or raised shingles, and whether debris has built up in valleys (the V-shaped channels where two roof planes meet).
Moss is everywhere in the Portland area. It grows in the shade, thrives in wet winters, and is completely normal on roofs that have not been recently treated. The question is not whether moss is present. The question is how bad it is, how long it has been there, and whether it has caused damage underneath.
- There is a light green tint or thin moss layer on the surface. Early-stage moss is a maintenance item. Zinc strips at the ridge, a chemical treatment, or a professional roof cleaning can address it. It does not indicate structural or waterproofing failure on its own. Worth noting
- Thick, raised moss is visible from the street and is clearly lifting shingles. Heavy moss holds moisture against the shingles and grows underneath them, physically raising the edges. This breaks the seal between shingles and creates an entry point for water. The older and thicker the moss, the more likely there is damage underneath. Look more carefully
- Debris has built up in the roof valleys or against vertical walls. Roof valleys are already the highest-traffic water path on the roof. When leaves and debris dam them up, water backs up and finds gaps in the flashing or shingles. Valley debris combined with age is a common indicator of leak potential. Look more carefully
- You cannot tell what condition the shingles are in because moss covers most of the surface. A fully moss-covered roof can be hiding anything from a perfectly good shingle to a rotted deck. This is exactly the situation where an inspector walking the roof gives you real information. Do not assume the roof is fine just because you cannot see problems. Ask your inspector
Deep dive: Why Proper Roof Flashing Is Critical
How flashing failures lead to costly water damage in Portland area homes
Area 04
Flashing at Chimneys and Walls: Where Most Leaks Start
What to do
Look at every point where the roof meets something vertical: the chimney, a dormer, a wall, a skylight. You are looking for metal flashing that seals these transitions. From the ground, look for lifted edges, visible rust or discoloration, and gaps where the flashing meets the masonry or siding.
Flashing is thin metal installed at roof transitions to direct water away from the joint. It is one of the most common sources of active leaks in otherwise adequate roofs. Even a roof that is only 10 years old can leak badly if the flashing was installed incorrectly or has since corroded or pulled away from the wall.
- You can see rust streaking down the chimney face or wall below a flashing joint. Rust staining below a metal flashing is often the first visible sign that the flashing itself is corroding or that water has been running down the face. The leak may be intermittent and only visible during heavy rain. Look more carefully
- The flashing at the chimney base looks lifted, separated, or patched with caulk. Caulk over flashing is a temporary repair, not a system. Proper chimney flashing uses step flashing and counter flashing that physically overlaps. If the entire seal depends on a bead of caulk, it is only a matter of time. This needs inspector evaluation. Ask your inspector
- There is no visible flashing where a roof section meets a vertical wall. Every wall-to-roof transition needs step flashing. If you cannot see any metal at that junction, it is possible the flashing is hidden under siding correctly, or it is possible there is no flashing. This is always worth asking your inspector to verify. Ask your inspector
- A skylight is present. Skylights are not problems by themselves. But skylight flashing is a common failure point, especially on older installations. Note its presence and ask your inspector to look carefully at the seal and any interior staining around the frame. Worth noting
Area 05
Gutters and Fascia: The Overlooked Roof Edge
What to do
Walk the perimeter of the home and look up at the gutters from below. You are looking for whether they are full of debris, whether they are pulling away from the fascia board behind them, and whether there is rust, damage, or granule buildup visible in the trough.
- The gutters are full of leaves and debris. Clogged gutters are a maintenance issue. They cause water to back up under the roof edge, overflow against the foundation, and accelerate fascia rot. It is easy to dismiss as cosmetic, but full gutters that have been ignored for years often mean the fascia behind them is rotting. Worth noting
- The gutters are pulling away from the fascia in one or more sections. This can mean the fascia board itself is soft and rotting (no longer holding the gutter spikes or screws), or the gutters were installed with inadequate slope and the weight of standing water has pulled them down. Either way, look at the condition of the fascia board where the gutter separates. Look more carefully
- There are heavy granule deposits at the downspout discharge or visible in the gutter trough. Granules in the gutters mean the shingles are shedding their protective surface. This is one of the most reliable signs that asphalt shingles are nearing the end of their life. You can often see granule buildup at the downspout splash block without getting on a ladder. Look more carefully
- The fascia board shows soft spots, dark staining, or paint that is bubbling and peeling. A visibly deteriorated fascia behind the gutter means water has been getting behind the gutter for some time. The question is whether that damage has extended to the roof decking above it, which your inspector can check from inside the attic. Ask your inspector
Area 06
Vents and Penetrations: Every Hole Is a Potential Leak
What to do
Look at the roof surface for plumbing vent pipes, exhaust vents, and any other penetrations. Each one has a rubber or metal boot around the base where it exits the roof. You are looking for cracked, collapsed, or missing boots, and for any penetration that appears to be sealed only with caulk.
- There are multiple plumbing vent pipes visible on the roof. Plumbing drains need venting, and most vents exit through the roof. Multiple vents are normal. Each one has a rubber boot that deteriorates over time, typically after 10 to 15 years. Note the count and pass it to your inspector so they can check each boot. Worth noting
- A rubber boot around a vent pipe looks cracked, collapsed, or missing. From the ground with binoculars, a failed boot often looks like a vent pipe with no visible seal around its base. Rain runs straight down the pipe and into the framing cavity below. It is one of the most common sources of interior ceiling stains. Look more carefully
- You see what looks like a patched or caulked area around any roof penetration. Caulk fails. Proper boot seals are mechanical and do not rely on caulk as the primary barrier. If someone has caulked around a vent base, it means the original seal failed. Ask your inspector whether the correct boot is still in place beneath the caulk. Ask your inspector
Deep dive: Thermal Imaging on Every Inspection
How Russ uses infrared cameras to look for temperature differences that can point to hidden moisture
Questions to Bring to Your Inspector
These are not things to resolve at the showing. They are the specific questions worth asking once you have an inspector in the home.
Inspector Checklist
Roof Plane and Structure
0 of 3 items verified
- Is the ridge line straight and level, or is there evidence of structural movement?
- How many layers of roofing are present? Is a full tear-off required at next replacement?
- How does the roof’s age compare to the typical service life for this material?
Inspector Checklist
Shingles and Surface
0 of 3 items verified
- What is the approximate age of the current roof? Do the shingles show signs of granule loss or cupping?
- Did you see any areas of impact damage, cracking, or missing shingles?
- Is moss causing active shingle damage, or is it surface-level and treatable?
Inspector Checklist
Flashing, Penetrations, and Gutters
0 of 4 items verified
- Is the chimney flashing properly installed with step and counter flashing, or is it caulk-dependent?
- Are the vent pipe boots intact? Are there any signs of active leaking at penetrations?
- Is there evidence of rot in the fascia behind the gutters? Has water reached the roof decking?
- Was there any attic evidence of an active or past roof leak?
Common Questions
Roof Showing FAQ
Sometimes, yes. Missing shingles, a sagging ridge line, and heavy moss lifting shingles are all visible from the ground and indicate real problems. But a roof can look acceptable from the street and still have significant issues: cracked flashing, failed seals around vents, or soft decking underneath. A ground-level look tells you what to ask about. An inspector walking the roof can document its visible condition.
Not automatically. Surface moss is common in the Pacific Northwest and can be treated with zinc strips or roof cleaning. What matters is whether the moss is actively lifting shingles, whether it is concealing deteriorated material underneath, and how long it has been ignored. A thick, old moss layer on an aging roof is a different conversation than a light green tint on a 5-year-old roof.
Look at whether the gutters are full of debris, whether there are shingle granules visible in the gutter troughs or at the downspout discharge point, and whether the gutters are pulling away from the fascia. Heavy granule loss in gutters is a common sign that asphalt shingles are nearing the end of their life. You can often see gutter condition from the ground without a ladder.
Standard 3-tab asphalt shingles are rated for 20 to 25 years. Architectural shingles typically run 25 to 30 years, sometimes longer. In the Portland area, heavy rainfall and frequent moss growth can shorten that lifespan. A roof at 20 years is not necessarily failing, but it needs to be evaluated carefully. Ask the listing agent for documentation of the last replacement. If they do not have a date, an inspector can often estimate age from shingle condition.
Flashing is the metal material used to seal roof transitions: where the roof meets a chimney, a wall, a skylight, or a plumbing vent. It is one of the most common sources of active roof leaks. Even a relatively new roof can leak badly if the flashing was installed incorrectly or has corroded. From the ground, look for visible gaps, rust, or lifted edges at any chimney or wall junction.
It depends on the inspector and the conditions. Russ Motyko walks roofs when pitch and safety conditions allow. When a roof cannot be safely walked, he uses a drone to inspect it. Either way, the roof is looked at up close, not just viewed from the ground with binoculars. This is worth asking about when you book any inspection.
