Two Tile Re-Roof Proposals, Same House: Where The Money Actually Went

Score the paper, not the pitch

The method is simple and a little boring, which is the point. Take both written proposals - not the conversation, not the brochure, the proposal - and build a table. Down the side, every item a tile re-roof has to address. Across the top, what each proposal actually says about it. Where a proposal is silent, write "not stated". Do not fill the blank in for them.

On this roof that produced twenty-five rows. Ten were even: tile attachment foam, hip and ridge attachment, eave closure, valley metal, five free sheets of decking, workmanship term, insurance, permits, property protection. Both roofs would have been built properly on those points.

Fifteen rows differed. Most of the difference was concentrated in two places.

Difference one: what is under the tile

Proposal A put two layers on the deck: a mechanically fastened anchor sheet nailed to the plywood, then a self-adhered cap sheet over it. Proposal B put one layer down: a self-adhered membrane glued directly to the plywood.

Both are legitimate, code-approved tile underlayment systems. They are not the same system, and the difference is not cosmetic. A one-ply direct-to-deck membrane seals the plywood from above and leaves no air path between the membrane and the wood. A two-ply assembly with a nailed anchor sheet does not glue the waterproofing to the deck. Why that matters is a post of its own: what the manufacturers say about direct-to-deck peel-and-stick.

To be fair to the one-ply system: a self-adhered membrane bonded straight to the deck carries a higher tested wind-uplift rating, and it is the assembly that earns the secondary water resistance credit on a wind mitigation form. If a proposal offers it, that is not a corner being cut. The question is whether the proposal also addresses what sealing the deck does to the attic.

Difference two: whether the attic can breathe

This is the row most homeowners never think to look for. Proposal A added sixteen low-profile tile vents and replaced four goosenecks, sized to the building code's net free area for the attic. Proposal B removed and replaced the existing goosenecks and added nothing.

On a roof with a self-adhered membrane across the whole deck, that is not a small difference. Both underlayment manufacturers say so in their own published documents - one calls its membranes "moisture and vapor barriers" and states that the space under the deck "must be properly ventilated"; the other says that where full-coverage application is wanted, "proper venting of the structure is required". A sealed deck with no added exhaust leaves the attic, the air handler and the ducts in it carrying the heat all summer.

Ventilation is arithmetic, not a feeling. Attic floor area, divided per the code ratio, gives a net free area; the number of vents follows. A proposal that does not state it has not done it.

The rows people skip

• Hip and ridge board. One proposal included it; the other stated ridge metal and did not mention the board. "Not stated" is not "included".
• Drip edge. One stated 2x2, 26-gauge, prefinished. The other stated "2x2 or 3x3 galvanized to match existing", gauge not stated.
• Wood allowance. One included about 32 feet of fascia and a per-foot rate after that; the other included none, at a higher rate, with specialty wood from three times that. On an older house this row alone can swing the final invoice.
• Wall flashing and stucco. Both priced per foot "if required". Compare the rates - and ask who patches the stucco.
• Gutters. One proposal does gutters in house under the same licence. The other declined gutter work and disclaimed responsibility for gutter damage. Read that sentence twice before signing.
• Uplift testing. Included where the municipality requires it, or not mentioned. Some Palm Beach County jurisdictions require it on tile.
• Underlayment warranty term. Stated (30 years) versus "registered on completion" with no term given.
• Payment schedule. How much is paid before anything is on the roof? One schedule asked for 10% before work started; the other asked for 40% before dry-in.

What the table is for

It is not for proving one contractor is honest and the other is not. Every item in the table is something a contractor can legitimately include or exclude; the price follows. The table is for making sure you are paying for what you think you are paying for, and that "not stated" items get confirmed against the full contract before the deposit leaves your account.

On this roof the table came out 15 to 0 with 10 even. Yours may come out differently. Build it anyway.

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