Sheet-metal roofovers are an effective way to re-roof a mobile home without ever exposing the inside of the building to the elements. Installed over the existing roof, roofovers can add beauty and extra thermal protection while leaving the integrity of the original roof intact. The procedure can be done by the homeowner with fairly common hand tools. Kits are available from metal roofing companies that will provide all the sheet metal, metal shapes, gasket materials and screws needed to complete the job. Does this Spark an idea?
Purlins
Purlins are long boards, usually treated 1-inch-by-4-inch boards at least 8 feet long, that act as supports for the new roof and as a spacer to allow an airspace between the new roof and the old. This airspace acts as insulation from solar heating by allowing hot air to escape and fresh, cooler air to be drawn in. Lay a purlin down lengthwise (horizontal) along the roof starting at the bottom edge. Screw the purlin down to every rafter it crosses with two screws. Place the next purlin in series, end to end, and screw it down. Continue to the end of the roof then move over 24 inches and start another run of purlins. Continue until the whole roof is stripped with the purlins.
Roofing
Metal roofing material comes in a variety of shapes and colors. From ribbed and colored to corrugated galv-alum, there is an appropriate style for any situation. Roofing will come in sheets that are factory cut to length. Lay the roofing across (side to side) the roof starting at one end and square with the building. Lay out and interlock the first three sheets of roofing to check for runout, then screw the first sheet down to the purlins. Remove the second and third sheets and apply the rubber gasket material to the leading edge of the first sheet. Position the second sheet and screw it down to the purlins and along the overlapping rib section. Repeat until the whole roof is covered.
Finishing
Gutters, soffit metal and ridge caps (if applicable) go on last and provide the final waterproofing and the finished look of the roof. Soffit metal helps cover any rough edges or raw wood that may need to be hidden. Ridge caps are used only on pitched roofs, not flat roofs, though mobile homes rarely have completely flat roofs. The pitch, however slight, sheds water down the metal sheeting. Attach the gutters below the edge of the roof anywhere that you need to divert water shedding off the roof.
Tags: down purlins, first sheet, flat roofs, purlin down, roof starting
