(not available for machine system.) 5.3 high fixed clips shall be 4 â in height to accommodate a 1 thermal space for added insulation at the purlins. (not available for machine system.)5.4 high or low floating expansion clips shall be either 3 â or 4 â in height (see contract drawings).
1 The total cost for a basic 200-square-foot screened-in porch will range from $766 to $1,025 or an average cost of $4.48 per square feet. 2  The cost of materials for a top-of-the-line screened-in porch on an existing deck runs between $860 and $1,070 with an installation cost between $297 and $304.
Size. The size of your porch greatly affects its cost. A small, do-it-yourself porch costs $50 to $2,000, as of 2010, according to Cost Helper.Larger porches that require foundations start about $15,000.You will spend much less on a basic, concrete-slab porch vs. a larger, screened-in porch or sunroom. Prefabricated porches cost approximately $10,000 to $20,000, while a custom porch built by a contractor can cost $45,000, according to Cost Helper.arger porches that require foundations start about $15,000. You will spend much less on a basic, concrete-slab porch vs. a larger, screened-in porch or sunroom. Prefabricated porches cost approximately $10,000 to $20,000, while a custom porch built by a contractor can cost $45,000, according to Cost Helper.