Retro Fitting a Metal Building With New or Additional Insulation
Thermal energy loss is one of the largest drains and expense in a building owner’s budget. Insulation materials have remained quite consistent with pricing over the past few years while energy costs are soaring. This makes re-insulating a viable, quite attractive investment for the metal building owner and user. The owner of Metal Building Insulation, a national supplier of insulation products states “It is all about the cost of ownership, employees comfort and payback of the initial re insulating investment through the savings of energy costs. Adding additional insulation to any climate controlled environment will pay for itself, it is just a matter of how soon. Owners may need help in this area. This is our area of expertise to compare the benefits in terms of cost with using different R-values for their particular building size. Additional paybacks are achieved through taking advantage of the IRS tax credits offered by the US government through the year 2007 when upgrading the energy efficiency for a commercial building.”
At Metal Building Insulation over 50% of our Vinyl faced fiber glass insulation volume on a national level goes into a metal building Retro-fit application. In the past we only supplied Fiber Glass insulation for new construction and now some of our largest projects are existing facilities. With access to over 400 installers and 50 different laminating and shipping points nationally for laminated fiber glass products we are in a position to meet the expected industry wide boom over the next 2 years for re- insulating existing metal buildings. The building owner can take measures for increasing the efficiency of the building with HVAC and insulation up grades or basically he can pay the utility company the rest of his life. Adding additional insulation to an existing metal building does not require technical or skilled labor. In other words it is not a hard to understand process but patience helps to get a quality finished look. It does require the proper equipment and safety gear as required from OSSA. Heights are dangerous so make sure you are adhering to all the regulations.
CHOOSING YOUR FIBER GLASS BLANKET SIZES
The key is to hold the insulation blankets up in the cavity between the purlins. The most common method of adding insulation to a METAL BUILDING ROOF is the “banding System”. Typically the metal building purlins are 60” or 5’ apart. In these cases a 5’wide fiber glass blanket is standard. For purlin spaces that are custom or random our blankets are factory pre- cut to fit the existing purlin spacing prior to the lamination of the vinyl facing.
All rolls are then labeled with the sizes to help insure that the sizes are placed in the proper space. The factory pre-cut roll length is then determined usually by the spacing of the bays or the distance between the rigid frames. Steel bands 1” wide (depending on the supplier) are screwed to the under side of the metal purlin 30” apart creating a grid system in the roof. The purlin depth can vary with 8” being the most common. The factory pre-cut rolls are then fed through, above the steel bands through the length of the bay. This can be a relatively easy process and can turn challenging when the roof area is not open, full of mechanical, electrical or other obstacles. In these cases shorter length blankets are recommended with taping of the seams for a finished look.
CHOOSING A FACING
Your facing is the material (white or black vinyl or polypropylene) used as the finished vapor barrier cover which is laminated to and over the fiber glass blankets. The most common facing is WMP-VR-R which is a vinyl reinforced product. Up grades are available for increased durability and strength. For instance to go to a WMP-50 facing which is twice as strong it is only about 4 cents additional per sq foot.
The tab is the extension of the vinyl facing past the fiber glass blanket which in retro-fit is usually 3” on each side. This tab is either tucked up along the side of the fiberglass acting like a trim or used to cover the bottom of the purlin. If it is glued it can then be considered a vapor barrier. To prevent additional heat transfer a 2” wide strip of rigid board acting as thermal blocks can be fastened at the bottom of each purlin along the entire length of the building.
Wall installation is much like the roof. The girt spacing will vary for the different eave heights and wind loads in a metal building. Typically the first girt is 7’4” above the floor with the additional girt spacing being 6’ or less. When the spacing is less than 6’ we factory pre-cut the roll width and length to the proper size then laminate the fiber glass and label as wall and the location which it is to be installed similar to the roof. For the first girt area of 7’4” the blankets are install up and down. A base angle must be installed at the floor the perimeter of the insulated area.
This base angle will provide a attachment point for the steel banding running vertical at the base as well as a place to help seal the bottom and help prevent the fiber glass from being in contact with moisture. A common option available from our company is a taped tab. This is a tab or extension of the facing which covers the base or a seam where 2 pieces of insulation come together. This tab has a factory pre-applied adhesive (double faced tape) which the installer peals paper off to stick once the insulation is in place. This makes it easy to seal the seams.
STICK PIN INSTALLATION
A common retro fit installation for the (clean steel surfaces) walls utilizes a “stick pin” that is glued onto the steel panel surface then used as a hanger for the insulation blankets. A common retro fit installation for the (clean steel surfaces) walls utilizes a “stick pin” that is glued onto the steel panel surface then used as a hanger for the insulation blankets.
To determine the quantity of pins needed for your job, figure (1) pin per square foot for the total area that is to be insulated. This will give you the pin quantity. The cost of pins will vary for the length (insulation thickness) but for budget purposes you can use 24 cents each plus $60.00 per gallon of glue which will supply up to 750 pins on average.