Local Information Archives | Green Door Home Inspections Ltd.

Roof flashing at chimney transition -- Green Door Home Inspections

What is Flashing on a Home?

April 6, 2026/0 Comments/in Inspections, Local Information/by Cody

By Green Door Home Inspections | Castle Rock, CO

Flashing comes up in almost every inspection we do. Most buyers see it flagged in their report and have no idea what it is. That’s not surprising — it’s one of those things that blends into the roof and disappears. But it does an important job, and when it fails, the consequences show up inside the home.

What Is Flashing?

Flashing is thin metal — usually aluminum, galvanized steel, or lead-coated copper — installed at transition points on the exterior of a home to direct water away from vulnerable areas. Wherever two surfaces meet at an angle, or wherever something penetrates the roof or wall, water has a path in. Flashing closes that path.

It’s not decorative. You’re not supposed to notice it. It just sits there and keeps water moving in the right direction.

Where It’s Installed

Flashing shows up in a lot of places on a typical home. The most common locations we inspect:

Chimneys — step flashing up the sides, counter-flashing embedded in the mortar, and a saddle or cricket behind the chimney to shed water
Roof penetrations — vent pipes, exhaust flues, and other items that pass through the roof deck each need a collar or boot flashing sealed around them
Roof-to-wall transitions — where a roof surface meets a vertical wall, step flashing weaves between each course of shingles
Valleys — where two roof planes meet, valley flashing carries water down and off the roof
Drip edge — metal strip along the eaves and rakes that directs water off the roof edge and away from the fascia
Kick-out flashing — a specific piece at the bottom of a roof-to-wall transition that diverts water away from the wall instead of letting it run down behind the siding
Skylights — integrated flashing systems around the frame
Deck ledger boards — where the deck attaches to the house, flashing keeps water from getting behind the siding at that connection
Windows and doors — head flashing above openings directs water away from the frame

What We Look For

Missing flashing. The most serious finding. Common spots where it gets left out entirely: kick-out flashing at roof-to-wall transitions, drip edge on rakes, and step flashing on re-roofing jobs where the installer cut corners.

Improper installation. Flashing that’s installed in the wrong order, lapped the wrong direction, or nailed through the face (which creates a penetration instead of sealing one) doesn’t work as intended even if it looks present.

Sealant used as a substitute. We see this constantly — caulk or roofing cement applied where properly lapped flashing should be. Sealant cracks, shrinks, and fails. It’s a temporary patch, not a fix.

Corrosion and damage. Flashing has a long service life when installed correctly, but it does corrode — especially at dissimilar metal contacts or in areas with standing water. Significant corrosion means it’s no longer doing its job reliably.

Loose or displaced flashing. Wind, thermal movement, and settling can pull flashing out of position over time. A piece that’s lifted or separated at a seam is an open door for water.

Why It Matters

Flashing failures are one of the most common causes of water intrusion in homes. The damage doesn’t happen overnight — water works its way in slowly, often for years, before it shows up as a stain on a ceiling or rot in a wall. By the time it’s visible inside, the damage behind the wall is usually significant.

The repair cost for a flashing issue caught during inspection is a fraction of what it costs after water has been getting in for a season or two.

What Happens When We Flag It

Flashing deficiencies range from straightforward to involved depending on where they are and how the roof is constructed. A missing kick-out flashing is a relatively simple addition. Step flashing on a chimney that was done wrong on a recent re-roof is a bigger job — the shingles in that area have to come up to do it right.

In either case, the work belongs to a qualified roofing contractor. This isn’t a caulk-and-move-on situation.

For Sellers: Get Ahead of It

Flashing issues are among the most predictable findings on older roofs and on homes that have had roofing work done. If your home has been re-roofed in the last decade, it’s worth having the flashing transitions checked before listing — re-roofing jobs frequently skip or shortcut flashing details that weren’t visible from the ground.

Reach out to us directly to learn more about our pre-listing inspection service.

Bottom Line

Flashing is invisible until it fails. When it does, the evidence shows up somewhere else entirely — a water stain, soft drywall, rot in a wall cavity. We check every accessible flashing location on every inspection because catching it early is almost always cheaper than finding out after the fact.

Questions about a flashing finding in a Green Door report? Call or text us at (720) 598-0111. We’re available 8am–8pm, seven days a week.

Green Door Home Inspections serves the greater Denver metro and southern Colorado, including Castle Rock, Parker, Lone Tree, Highlands Ranch, Centennial, Littleton, and surrounding areas. Same-day reports, every inspection.

Guide to local Contractors

March 27, 2026/3 Comments/in Local Information/by Spectora

When you need repairs on your home, it may be a little daunting trying to find a reputable contractor to call. I always recommend using a locally owned company that has the proper license to perform the work. They should be able to verify that for you at any time. Use this list as a good starting point for hiring professionals in Castle Rock, Douglas County, and the Front Range.

Handyman – Skilled Handyman Services CR
Garage Door Repairs –Aeonic Garage Door and Repair
Roofing and Exteriors– Columbine Roofing and Exteriors
Plumbing– Trusted Plumbing Services
Electrician– The Right Connection Electric
Exteriors and Paint – Columbine Roofing and Exteriors
Heating/Cooling/Ventilation–Avalanche HVAC Services
Fence and Landscaping–Grizzly landscaping and Fence
Radon Mitigation Installer– Aristeia Radon
Discounted Home Radon Monitors – Ecosense
Solar Panel Installation and Inspections – Mountain bear Electric
Sewer Line RepairsTrusted Plumbing Services
Lawn and Sprinkler–Natures Carpet
Concrete and Flatwork –LevelUp Concrete Raising

*If you don’t see a category listed here to meet your needs, contact us for current partners and recommendations. These recommendations are based on experiences personally or professionally. They are for informational purposes only. You do not need to use these specific companies in order to perform any recommended repair from an inspection report. This is simply a courtesy starting point.

Radon Testing, at a glance.

September 30, 2023/6 Comments/in Inspections, Local Information/by Spectora

Your Real Estate Agent or Home Inspector may be suggesting that you do a “Radon Test” before you move into your new home. What is Radon and how is it tested?

Here are some quick facts to grasp the concept and links to more information.

What is Radon

Radon is a radioactive element that is toxic, colorless and odorless.
Radon is in nearly all soil types and gets into a home through gaps/cracks in the home and foundations. Basements usually have the highest concentrations of Radon.
Radon is the leading cause of lung cancer among non-smokers, and second among smokers. Read more here.
On average, indoor Radon levels in Douglas County (Colorado) are approximately 50% higher than the recommended “Action Level” set by the U.S. EPA.

How do we test for Radon?

During a typical home sale, we do a “short-term test” that is roughly 60 hours in total. This means that a test device is strategically placed in the home 60hr radon test begins. The 60 hour test consists of a 12 hour delay, followed by 48 hours of recorded testing. After the test is complete, a report is generated that shows the average radon levels in the home during that time.

Other notes to consider:

The test must completed in “Closed Home Conditions” (See the graphic below). This means keeping all windows and doors closed except for normal entry and exit, and not operating fans or other machines (Swamp coolers, whole house fans etc.) which bring in air from the outside . Fans that are part of a radon-mitigation system or small exhaust fans operating for only short periods of time may run during the test. Closed Home Conditions must be maintained 12 hours prior to the test, and for the duration of the 48 hour test. Our monitors include features that detect tampering of the conditions of the home, or of the monitors themselves.

The home will need to be accessed twice for approximately 10 minutes. Once to drop the monitor, and once to pick it up at least 60 hours later. If there is a home inspection scheduled with the radon testing, the monitor may be dropped off prior to the inspection so the results can be read at the time of inspection. Another option is to drop the monitor off during the inspection, and returning at least 60 hours later to gather the monitor and receive the report.

The EPA recommends taking action to mitigate Radon if the results of the test are 4.0 pCi/L or greater. (That’s Picocuries per liter, and I’m not going to define that here! It’s the number 4.0 that is important). The average indoor Radon level in the U.S. is 1.3 pCi/L. There is no “safe level” of Radon established by the EPA. It is up to the buyer or homeowner to take action or not.

Although a 48 hour test is typical for a home sale, long-term testing is more accurate. Long term testing will take at least 90 days, and usually isn’t possible during the diligence period of a home sale. If the initial test comes back high we recommend testing again, preferably for a longer duration. If there isn’t time for that, a Radon Mitigation system can be installed and another test can be completed later to verify the system is working as intended. Radon Mitigation systems typically cost $1500 to $2500, depending on the specific home construction, location and installation techniques.

Order a Radon Test HERE.

Colorado Radon Testing Laws. HERE (Effective July 2022)

10 step guide to preparing your home for Winter.

September 22, 2023/0 Comments/in Local Information, Maintenance, Tips/by Spectora

It’s that time of the year again! Take advantage of the Fall weather and knock out these 10 steps before the snow comes. A little maintenance goes a long way, and it isn’t very difficult.

1) Add caulking around doors and windows: Caulking is inexpensive, easy to install and very important for weatherproofing your home. Find the gaps and cracks on the interior and exterior and seal them up.

2) Replace worn weatherstripping around door jams: Weatherstripping is the rubber or foam strip that helps seal your doors. Over time, they wear out and let the conditioned air escape to the outdoors. Check the entire area around the door. If you can see daylight around the perimeter of a door when it is shut, you’re losing energy.

3) Drain irrigation systems: Water left sitting in the irrigation system can freeze and cause major damage. Hire a pro to blow out the system with compressed air and turn off the entire system until spring.

4) Disconnect hoses: Turn off your exterior water taps, drain the hoses and store them inside or in a garden box.

5) Check your downspouts: Accumulated snow on your roof will eventually melt, sending hundreds of gallons of water down the gutter system. Make sure it gets diverted away from your house with downspouts and extensions. Check the regularly for ice build-up and other clogs.

6) Have the chimney inspected: Even if you do not use your fireplace as a primary heating source, you should have the chimney inspected and cleaned every year. If there is a problem with your furnace, you will need heat until it is fixed.

7) Have your furnace serviced: It goes without saying, your furnace is incredibly important during the winter. An annual service by a professional will help keep it running smoothly and efficiently.

8) Store your mower: Gasoline engines need to be properly maintained and prepped for storage. Check the manufacturers recommendations regarding long term storage of the engine. You may need to drain fluids and use fuel additives. If your mower takes batteries, charge them up and store them indoors. They will last much longer.

9) Insulate water lines: If you have water lines running inside of an exterior wall, consider adding insulation to them. Check your basement, crawlspaces and garages as well. Freezing weather can wreck havoc on the water inside these lines. If you find a frozen pipe during the winter, call a professional plumber immediately. Attempting to thaw out a plumbing pipe can cause it to burst. Call a pro!

10) Service the water heater: Water heaters need maintenance as well, and they will inevitably be working harder in colder temperatures. Now is a great time to have a professional drain the tank and service the entire unit.

There are plenty of other steps you can take to prepare for the Winter months, but these are some of the most important ones. Most of these can be completed by yourself and a professional in just a couple days. If you want more information about your home and help deciding what needs to be done, consider an Annual Home Maintenance Inspection by a Certified Professional Inspector.

Do I really need a Home Inspection?

July 29, 2023/0 Comments/in Local Information, Tips/by Spectora

This is a booming Real Estate market. Homes are being listed and sold so fast (30days) that buyers are forced to make decisions quickly and make offers on the spot. One tactic buyers use is to forgo an inspection with their offer in order to convince a seller that they are ready to move in, no matter what. But, is that safe? Do you REALLY need an inspection here in Castle Rock, or anywhere else?

The answer is YES. Even the best kept home can have material defects and hazardous issues that you may not notice by just doing a simple walk-through. Are they selling with an unknown issue? Is there a leak behind that newly painted wall? Are there signs of mold or other air quality issues? Has there been mass water intrusion into the basement or crawl-space in the past? Are there repair costs that will affect your wallet down the road? The list goes on. So what is a buyer to do?

Stick to your guns. Schedule an inspection from a Certified Professional Inspector and move quickly. If all of your other ducks are in a row……(ie, pre-approval letters, down payment plans, earnest money etc)…. then find an inspector with flexible work hours and the ability to schedule quickly online. Show the sellers that you are motivated and ready, but smart.

Even if you have to adjust your offer (Higher) to be more attractive, you can save money in the long-term with an inspection. The cost of an inspection (we start at $365 for small homes) is pennies compared to the home values in the Castle Rock area (Estimated median house or condo value in 2016: $445,400) and NOTHING compared to expenses for major repairs in your house. Armed with a strong offer and a home inspection report, you can work with your realtors to negotiate a final sale price.

It’s possible to lose the negotiation battle when you demand an inspection first (I did!), but you will be much better off knowing that a qualified professional has helped you with your due diligence and is working for YOU. These homes are expensive and can be life-long investments. Don’t get wrapped up into the hype and purchase something you will regret later.

What's Included in a Home Inspection

Infographic courtesy of Spectora

Recently move to the Front Range?

January 29, 2021/0 Comments/in Local Information, Tips/by Spectora

Here are 5 tips for homeowners that are new to Colorado’s beautiful Front Range.

1) Hail is coming. Update your home and auto insurance if you need to. Park the cars in the garage. Keep the pets inside….etc. Do what you have to do, but the hail is definitely coming. Several areas along the Front Range are considered “Hail Alley”. Denver, Aurora and Colorado Springs are among the Top Ten most hail prone cities in the US. Start off with a thorough roof inspection, and have it checked out as often as needed throughout the year. A good rule of thumb is to inspect each year in the spring, and after any hail storms in your area. Most roofers do this for free or a minimal charge. When replacing existing shingles, ask your roofer about upgrading to a Class 4 shingle. The extra protection that class of shingle offers may better the best choice, and may lower your insurance.

2) It’s dry here. Contrary to popular belief the Front Range of Colorado is very dry, especially during the Winter months. Home humidity levels can easily drop to under 20% during the heating season and that can effect not only the comfort of your home, but individual health issues as well. Even wood furniture and cupboards can be negatively affected by low home humidity levels. Consider a running a humidifier near your bed when you sleep. Also, it is quite common in Colorado to install a “Whole Home” humidifier onto your forced air furnace. They usually cost a few hundred dollars, humidify the entire house and they do not require a lot a maintenance. Contact a qualified HVAC pro to look for options.

3) The sun. It matters. How would you like to never again have to shovel your driveway in the Winter? Do you like shade on the back patio or do you want to bake in the summer UV rays? The way your home is situated relative to the sun really does matter here. Year round, the sunlight is intense, much more intense than most other places in the US. Before you decide on a home, consider which direction the home faces and where the sun will be a various times of the year. You will notice North facing driveways are always full of snow and icy, while their neighbors across the street with South facing driveways are melted and clear by noon. In the summer, the back patio or deck may be too hot for activities in the afternoons, so folks will opt to hang out in the front of the house or garage where there will be more shade. Also, do not forget the building materials; Buy the UV protected paint for the house, Consider window treatments etc. You’ll even need to adjust your sprinkler heads in the lawn to account for direct sun. Trust me, the sun matters on the Front Range.

4) Expansive soil. An entire book could be written here, but I’ll give you the basics. There are certain types of soils in the ground in Colorado (actually clays, like bentonite) that can swell when they are exposed to ground water. They swell a lot actually. They swell so much that they can literally lift up the foundation of your house. So what does this mean for the typical homeowner? Keep water away from your foundation. Do yearly gutter maintenance, and check your home exterior, basement and crawl-spaces after any hard rains. This is important just about everywhere in the country, but the expansive soil here makes it even more important along the Front Range. Also, check with your local building department before your basement remodel begins. Many areas require a “Floating Wall” to be built to account for basement floor movement.

5) There is gas in your home. Radon Gas to be more specific. Radon is a colorless, odorless, naturally occurring yet highly dangerous gas that is very common in high concentrations in some soils. This gas can leak into your home through the basement or bottom floors and is actually the number 2 cause of lung cancer in the country. Sounds horrible you say? Well, it is very real and very dangerous, but it is also very easily mitigated. Most real estate transactions in Colorado will have a simple Radon test performed during escrow. Then, if necessary, a Radon Mitigation system can be installed on the home. These systems range from $500 to $2000 to install and require almost no maintenance. Your neighbor may need one, your home might not. You don’t know until you do a test. Get a test by asking your home inspector or real estate agent. Read more about Radon here.