Most sliding screen door frames we change out, is because the frame is bent due to someone walking into it. The original screens installed by the builder is usually very weak and come with plastic parts that do not last. We custom make screens on the spot, our service is mobile and when buying a screen door we highly recommend this type of service.
The doors we make are measured on the spot and made on the spot. This allows us to make sure the size is just right, the screen needs to slide slooth but not fall off the track. This is sometimes a bit hard when encasement are mostly off square an shorter in some areas and higher in others. This is not a problem for us, we have been doing it for 17 years and have no complaints, only good compliments.