Your Tampa Bay Window and Door Specialists- Replacement windows

Call Today! 727-442-3158


Window & Door Installation Tampa Bay

About Us



800 Belleair Road, Clearwater, Fl. 33756


Our showroom and parts department are open 8:00am-4:30pm, Monday thru Thursday, we close at 4pm on Friday.

Meet the Owner

My name is Mark Miller and I am the owner of Douglas Manufacturing.

In 1978, while attending Dunedin High School, I started working part time at Douglas Mfg. for then owners Dennis and Jacqueline (Jackie) Henegar. After graduating high school, I became a full-time installer for the company. In 1983 I married my high school sweetheart; Amy and we started our family. We have 2 children, son Mark Jr. who works for me as part of our service team and daughter Maryann who is a registered nurse. In 2001, Dennis decided he was ready to retire after many years and I was offered a sales position within the company, soon after I obtained my own contractors licenses and continued moving up in the company. I was offered the amazing opportunity to purchase the business upon Jackie's retirement in 2014.

Douglas Mfg was started in 1948 by Leeland Shales, Jackie's father. From the mid 1950's until August 2018 we were located at 1115 Cleveland St. We recently moved to our newly remodeled building at 800 Belleair Road in Clearwater. Come visit our new location to see our showroom and meet our knowledgeable parts department staff. Our showroom has operable full-size displays providing a hands-on experience for customers. Not only do we carry replacement parts, we also cut glass and mirror to size and have a screen department capable of repairing or replacing window screens and sliding screen doors.

We provide a range of services and specialize in residential window and door installation. We carry top of the line products to improve your homes energy efficiency and security alike.

We not only replace windows and doors, we also repair them. We have a service team, that can come to your home, who specialize in repairing windows and sliding glass doors. They also can replace broken or fogged glass, repair or replace window screens and/or sliding screen doors. If you're not ready to replace, repairing is a great option to extend the life of your current windows/doors.

Douglas Mfg has been serving Pinellas County for 70 years. All of our employees have been with the company for many years and take pride in providing quality work and excellent customer service before, during and after the sale. This forms an unstoppable combination that truly sets us apart.


Call (727) 442-3158 to schedule an appointment today.


Certified PGT Reglazers
Courses Completed-

PGT Florida Building Code Course
PGT Win Guard Product Training
Installing The PGT Way
PGT Wind Bourne Debris Protection
PGT Retrofit Course
PGT Sliding Glass Door Products Training
PGT Blue Print Course

Come and visit our window and door professionals at our local showroom in Clearwater, FL

We specialize in many different types of windows and doors, both non impact and impact resistant products.


We also carry different types of hurricane shutters, awnings, and screen doors.


Call Today! 727-442-3158