Re-framing a flat roof in preparation for
a new rubber membrane

For an existing addition on a circa 1912 residence in Newport, RI

Part I
Part II
Part III
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- 01 -

Thats me hauling the R-38 insulation up the ladder.

- 02 -

Filling the 2x10" rafter bays with a nice blanket of insulation.

- 03 -

To get a definite pitch for runoff Frank Harding is ripping 18' 2x8's on a diagonal. just measure up 5" alternately from the top and bottom at both ends and snap a line. Just cut down the center of line with the skillsaw to yield two identical tapered rafters.

- 04 -

Looks easy enough to get a nice pitch. The framing below however is far from flat so lots of shimming will be required.

- 05 -

Setting the new pitched rafters to stretched masons lines every 4 feet told us exactly how much shim action was needed at a given point. This is how to get a perfectly flat, no puddle roof with a 3 1/2" overall pitch.

- 06 -

Once every rafter was shimmed to the lines spaced every 4 feet, Alan nailed them off as I filled in the shimming between the lines.

- 07 -

It would have been a back breaker to lug up 20 sheets of 3/4 CDX plywood. Thankfully RiverHead Supply of Middletown RI has a boom truck.

- 08 -

Before insulating where the old porch hip roof was we need to add some framing for a new skylight. The bathroom below had no window so the skylight will give much needed light and ventilation. Alan Bettencourt is adding a 2x12" to stiffen the new roof framing in this area.

- 09 -

It feels good getting this plywood down. Now we have a very strong and perfectly flat roofing deck with a 3" pitch for runoff. (Did I just say deck, lol.)

- 10 -

This addition looks like a floating box. Roof overhang with a new cornice will make this building look like it was added on in 1900, not 1960. The original roof had no overhang. So this is why we left the plywood long, utilizing the full 8' sheets.

- 11 -

This 20'x35' roll of .060 rubber weighs a little over 300 lbs. They are predicting rain showers tonight and tomorrow, so we called in the big guns again.

- 12 -

Homeowner Steve looks on as Alan directs the big Peterbuilt for a perfect landing.

- 13 -

Before rolling the rubber out, we belt sanded all the plywood joints to remove any irregularities.

- 14 -

The 20 foot wide sheet comes folded over on a 10 foot roll.

- 15 -

Once the rubber was relaxed we folded it back on itself and applied the bonding adhesive.

- 16 -

Ahhh! A perfectly flat roof with 3" pitch over 20'

- 17 -

Alan Bettencourt deep in thought after a job well executed.

Part I
Part II
Part III
you are here