Rapid Commercial Roof Leak and Damage Repair in Simi Valley

RESIDENTIAL ROOF INSTALLATION, ROOF REPAIR & COMMERCIAL ROOFING

Call us today for a FREE ESTIMATE!

805-523-2550

YEARS OF EXPERIENCE AS ONE OF THE MOST RELIABLE Commercial ROOFING COMPANIES IN SIMI VALLEY, CA

When a commercial roof fails, it can disrupt your business and damage valuable inventory. Our crews are experts in commercial leak detection for flat and low-slope systems. Because we understand local Simi Valley codes, we prioritize minor repairs that fall under the 100-square-foot permit-free limit, allowing us to stabilize your facility immediately. We address common commercial issues like failed HVAC penetrations, membrane punctures, and drainage blockages, providing durable fixes that keep your business operational.

Commercial Project Tip: While many minor repairs under 100 square feet do not require a permit in Simi Valley, a full commercial re-roofing project involves a multi-stage inspection process with the city. We handle the entire permitting and inspection workflow to ensure your building meets current safety and Title 24 energy codes. You can view the full Simi Valley Installation Requirements on our city overview page.

GreatWay Roofing is an established and trusted Simi Valley roofing company that provides only the very best in craftsmanship and service. When you need a new roof, roof repair, or commercial roofing services, GreatWay Roofing is the company you can count on.

We conduct our Simi Valley Roofing business in a manner that elevates how roofing contractors are perceived by individual homeowners and commercial clientele alike. Customer service is paramount at GreatWay Roofing Company.

GreatWay Roofing
4518 Industrial St
Simi Valley, CA 93063
(805) 523-2550

Beyond the Membrane: Understanding Commercial Leaks

Many “roof leaks” on commercial buildings are actually caused by non-roofing components:

Debris in Drains: When drains are clogged, water pools on the roof, creating excessive weight loads and forcing water through the smallest imperfections.
Equipment & HVAC Platforms: Leaks often originate at the ducting platforms or where HVAC units are mounted rather than the membrane itself.
Aging Skylights: Failed seals around old skylights are a frequent source of water intrusion.

View all Commercial and Residential Simi Valley Roofing Services.

If the damage is too extensive, we recommend Simi Valley Commercial Re-Roofing.

Protect your assets with our Commercial Inspection & Maintenance plans.

CALL US TODAY FOR A FREE, NO-OBLIGATION ESTIMATE!

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MINIMUM ROOFING REQUIREMENTS

Listed here is a breakdown of the minimum roofing requirements based upon the most common existing roof coverings for Simi Valley.

Asphalt Shingle:

Tile:

Low Slope:

# of Layers

Max layers = 2

Max layers = 1

No addl. layers permitted

Added layers may require Engineer’s Report

Plywood

Use existing
Replace as needed

Min. Felt
Underlayment*

ASTM D226 Type I 15#)
30# recommended

ASTM D226 Type II (30#)
40# recommended

Not Applicable

Min. Fire
Rating

Class A Min.

Class B Min.
Recommended Class A

Color Restrictions

**No Restrictions**

Max. Weight

**6lbs. Per sq. ft. Over 6lbs. Requires Engineer’s Report**

*Roofs with a slope of less than 4:12 require a minimum of 2 layers of a 15lb. ASTM D226 Type I felt underlayment.

REVIEWS

WHAT OUR CLIENTS ARE SAYING

GreatWay Roofing

5.0

Based on 134 reviews

review us on

John Amaki

07:28 18 Jan 25

GreatWay Roofing did a fabulous job reroofing my house. It was priced right, fast, clean, and friendly. Shoutout to Tim, Tony, Rene and the crew for a great experience!

Griffin Cardew

15:51 03 Jan 25

Fantastic experience and professionalism from the team and company.

Ali Amini

19:31 25 Nov 24

Workers were polite and listened to my concerns and very professional. They did a good job and finished the job in a timely manner. I was very impressed with them. Next job, I call GreatWay.

Barbara Paige

21:38 24 Nov 24

Honest, professional, punctual, great communication.
Tim and Brandon sent updates at every step including pictures of their work in real time.
We are very pleased and have contracted them for another property.
Highly recommend.

Michael Kelley

14:28 24 Nov 24

Great experience with Greatway Roofing. I highly recommend Greatway Roofing for your roofing project. Fantastic team. Met with Matt and he gave me a very thorough walk through of options for underlayment, repairs and replacement for my roofing project. Matt knows his stuff and identified details of the job that no other roofer pointed out to me and I interviewed over 20 contractors. Matt’s knowledge and Greatway Roofing’s lifetime workmanship warranty won me over even though the cost was slightly higher than some of the other estimates I received. You know the old cliche ‘You get what you pay for’. Your roof repair isn’t something you want to cheap out on if you want quality. The roofing team worked their behinds off in the unusually high October temperatures over 100 degrees here in Santa Clarita. Kudos to Emilio and the roofing laborers. Matt, Sean and Cindy all pulled their weight as well. Regular updates of project status were provided with photos and video. All the inspections and permits were pulled and completed with the city of Los Angeles who can be difficult to work with considering their work load. Thank you to Greatway Roofing for your excellent service and expertise. I would definitely recommend this roofing contractor/team to anyone in need of roofing work.

Julie Lomakka

23:17 23 Nov 24

Everyone was very professional and on time. I am a real estate agent and had refered several clients to them in the past and they had all been happy with the results. My quote was fairly priced. Communication was excellent and the work was done in a reasonable amount of time. I will be using them again.

Teresa Schuberg

16:37 21 Nov 24

What a great experience. My old roof had given up the ghost, and I was on borrowed time. Matt from GreatWay came out and walked me through options. I liked his approach and company the most, so we went with them.

The price was great (as much as it can be for a roof, no small purchase), and the crew was really fantastic. They were professional and got the work done quickly. They had to put sheathing on my roof, since it’s old and didn’t have any underneath (!), and the whole project still only took 4 days.

For me, the best thing was that the crew cleaned up every day. The yard was clear, and there were no nails or debris hanging around. It’s a little thing that was really nice to see— it was really nice to go outside in the afternoon and not worry about stepping on anything/ having that peace to move around in the middle of a project.

I’d recommend this company to anyone.

Richard Kempton

20:56 28 Oct 24

GateWay did an excellent roof replacement.Everyone of the crew was professional & courteous. The job site was left completely clean each day, even after tear off. I would recommend them to any of my friends or family

Steve Patrick

19:56 24 Oct 24

I really appreciated Tim coming out and inspecting our flat roof for leaks that might be causing the dry rot under the eaves. Even though the roof looked fine, Tim caulked the area above the dry rot just in case. If we do decide to repair or replace the roof in the future, we’ll definitely be giving GreatWay Roofing a call.

Jesus Morales

19:10 22 Oct 24

Nancy Schmidt

20:02 16 Oct 24

I am so impressed with the ease of signing up for roof work without any cash upfront.
This company is a class act and I am so pleased to have picked GreatWay Roofing who kept me informed thru email and sent photos as the project was moving ahead.
Great customer service, knowledgeable courteous workers and a satisfied customer says it all

Christopher Gibson

11:47 16 Oct 24

Exceptional & organized. Every GreatWay team is performing efficiently. From the engineering bid, office updating videos, old roof removal, new wood facia, new roof installation and managing permits and final inspection. A+++++

Don Robinson

17:53 04 Oct 24

We had an excellent experience with GreatWay Roofing. Tim came by to give us an estimate related to some potential fascia board replacement work (and some additional potential work). The company that is installing our new gutters referred us to GreatWay. After doing a thorough inspection, Tim explained that we didn’t need their services at this time. He is a super nice guy, and he explained everything in great detail. If we ever need roofing work done in the future we will call GreatWay Roofing first and I would recommend them to anyone!

michelle schwartz

16:18 30 Sep 24

It was a pure pleasure working with Tim & GreatWay Roofing!!! Tim is very attentive and just plain nice, plus his pricing was competitive. He has an excellent crew that did a great job, finished as projected, and were very communicative throughout the process. I highly recommend this company for your roofing needs.

Liane Phillips

16:38 21 Aug 24

Working with GreatWay roofing from the start has been a good experience. They all were timely, polite, professional and worked hard to make sure we would be satisfied. We highly recommend them for any roofing needs.

E Gh

00:39 13 Apr 23

I could not be more satisfied with the work done by this roofing company. From the initial underpayment to the final tile installation, every step of the project was handled with precision and care. Matt's communication and attention to detail were top-notch, and Marco and his crew were true professionals who delivered exceptional results.

Laysa Malcolm

04:51 26 Oct 22

We received several quotes for a new roof...Greatway's price was one of the least expensive. Aside from the cost, we decided to have them do the work because they seemed very honest and easy to work with. We had a tight schedule to get it done and Matt came through for us. Other companies were quoting 7 to 10 days and weren't sure they could complete it by our deadline. Matt and his crew completed the task in two days...Greatway is a great company to work with.

Brad B

23:40 26 Sep 18

Matt and the team at Greatway roofing just finished today reproofing our home. They did a tremendous job. Matt did an excellent job with expectations and things to consider with our project. They started the project on time completed the project on time and there was no surprises. We received photos or a walk through of any issue or situation that arose. Communication with them and Matt's communication with other contractors was excellent. I would highly recommend them. Thank you, Matt and Greatway Roofing Team.

Rose Van Wier-Hein

17:58 07 Aug 17

Thank you so much GreatWay Roofing for donating and replacing the roof of a cabin at Golden Heart Ranch. We are a ranch dedicated to improving the lives of special needs young adults and the addition of this roof means we can now have a sleep away camp. We could not have the cabin up and running without your generous donation! Everyone that came out to help was kind, professional and caring. You guys are awesome... thank you from the bottom of our hearts!