Satisfactory product performance depends on proper installation
We recommend that you get a professional installer like Natural
Light Skylight Inc. to install the skylight or roof window for you.
Nevertheless, installing a skylight can be performed by homebuilders
with advanced construction skills. In the following we show you an example
for a fixed skylight installation. This will give you an idea about
the level of difficulty and the necessary considerations you have to
make for the installation job.
Installation instruction for fixed skylight VELUX® FSF/FS. 
Disclaimer:
- The installation
instructions on Natural Light Skylight Inc. web-site do not replace
the instructions coming with the product.
- VELUX® reserves
the right to implement product changes for improvements and change
the instructions adequately without prior notification.
- The seller assumes
no responsibility whatsoever for failure of an installer to install
VELUX® roof windows and skylights in accordance with these installation
instructions.
- The seller assumes
no obligation whatsoever for failure of an architect, installer or
building owner to comply with all applicable law ordinances, building
codes and safety requirements. (CABO National Evaluation Report -
NER 216)