Flat Roof Replacement in Morgan's Point

Because wind uplift concentrates at edges and corners rather than in the middle of a roof. A membrane that is merely adhered starts to go there, and once an edge lifts the wind gets underneath and the rest follows quickly. Mechanical perimeter fixing is the design here, not an upgrade.

Not in itself -- water that clears within a day or two of rain is normal. Water still there a week later is a seam being tested continuously, and it usually means the fall does not actually run or the outlet is not at the low point.

Not on age alone -- but on this coast there is a second question that matters more. A 20 year old architectural roof is middle-aged by material standards, so the usual tests apply: granule loss, brittleness, how flat the covering lies, whether the deck is sound. Then ask how it was fastened. A roof fitted 20 years ago may have been stapled, or nailed to a pattern that predates the current wind requirement, and on a bay-shore house that matters more than how the shingles look.

It is a Florida rule and it has no force in Texas. The 25% rule comes from the Florida Building Code Existing Building, where repairing or replacing more than a quarter of a roof within a year can trigger a requirement to bring the whole roof up to current code. Texas has no equivalent provision, and La Porte's requirements are set out in its own roofing policy instead. Anyone quoting the 25% rule at you in Texas is citing the wrong state's code book.

In La Porte, yes -- a roof replacement needs a permit whether you are hiring somebody or doing it yourself. Texas has no statewide answer to this because permitting is municipal, which is why the question keeps getting answered badly online. Doing it yourself also does not exempt the roof from the specification: the 150 mph shingle requirement and the nails-not-staples rule apply to the roof, not to who fitted it, and the certification letter still has to reach the city inside 30 days.