Part of the Thermaglaze group est. 1988

Double glazing in Yeovil

Welcome to Firmseal's website where you will find all the information you need regarding our range of innovative double glazing and home improvement solutions.

As part of the renowned Thermaglaze Group, Firmseal offers the very latest in glazing technology for windows, doors, conservatories and orangeries in uPVC and aluminium, garage doors, and maintenance free roofline products. We also install leading-edge solar PV systems which are proven to provide our customers with long-term money-saving opportunities on their domestic energy bills — plus great tax free returns on their investment. Based in Yeovil, Somerset we serve all of the surrounding counties within a 50-mile radius.

Established since 1988, the Thermaglaze Group has an unrivalled reputation for quality and customer service. This is illustrated by thousands of genuine testimonials, some of which are published on this site.


"I am delighted with my new windows and door and have only praise of the highest standard for the whole experience. It's great not to have pressure put on you. Keep up the good work" Mrs T, Yeovil