Roofing

Sizing a Dumpster for a Roof Tear-Off

Roofing is where sizing goes wrong most often, and here it is usually one of two things: a hidden second layer, or concrete tile.

The one number that matters: squares

Roofers measure in squares. One square is 100 square feet of roof surface. A typical Visalia single-family home runs somewhere between 18 and 32 squares, with the newer subdivisions tending toward larger footprints and lower pitches.

If you do not know your square count, your roofer does, and it is the first thing to ask.

What a square of roofing weighs

The spread is the point. Concrete tile is roughly three to five times the weight of composition shingle for the same area, and about ten times the weight of foam.

Composition sizing table

For tile, ignore this table entirely — see below. For foam, size up.

Concrete tile is a different calculation

Run the arithmetic on a tile roof. A 28 square roof at 1,000 lb per square is 28,000 pounds — fourteen tons of tile before underlayment or anything else.

Two further points that matter on tile jobs.

Tile breaks as it comes off, so it occupies more volume than the intact roof suggests while weighing exactly the same. Broken tile also loads awkwardly and settles.

A great many tile "replacements" are not replacements. On these roofs the tile is often sound and the underlayment beneath it has failed. In that case the tile is lifted, stacked and re-laid over new underlayment — far less waste and a much smaller container. Ask your roofer which job you are actually having done before booking anything from us.

Foam and flat roofs

Common on flat and low-slope sections — additions, patio covers, garages and a good deal of the commercial stock along the older corridors.

Foam is the opposite problem from tile: extremely light and extremely bulky. A foam tear-off fills a container's volume while barely registering on the weight allowance, so these jobs size up — a 20 or 30 yard for what looks like a small roof.

Break it down as it is loaded; foam comes off in large irregular slabs that trap air. And keep it covered between sessions, because it is light enough to blow out of an open container in a valley wind event — which, under Regulation VIII, is also somebody's dust problem.

Many foam roofs are recoated rather than stripped, producing almost no waste at all. Again — ask which job it is.

The second layer problem

Plenty of houses here have a second layer of composition laid over the original, and it roughly doubles the tear-off weight.

Look at the rake edge from the ground, where a double layer often shows as a noticeably thicker band, and ask your roofer to confirm at inspection. If it turns up on the day, call us — a swap mid-job is far cheaper than an overloaded container that cannot legally be hauled.

Occasionally you find composition laid over an original wood shake, which is a third situation again and a genuinely different job.

Sun is what ages roofs here

Worth understanding, because it explains why replacement cycles surprise people who moved from cooler places.

This valley delivers long, intense summers with sustained high roof-surface temperatures and very little cloud. Ultraviolet exposure and heat cycling degrade composition shingle, underlayment and sealants far faster than moderate rainfall alone would suggest.

The practical consequences for the container:

• Underlayment failure is often the real job, especially on tile — and it is light, so it barely affects the weight.
• If the decking has gone too, the job changes character and adds real tonnage. Call us for a swap rather than overfilling.
• Summer compresses the working day. Crews start at first light and are frequently off the roof by early afternoon, so a job that takes three days in March can take five in July. Book the rental period accordingly and ask for an early delivery.

Placement, canopy and the nail problem

Roofing containers need to sit close to the house, and in Visalia that is usually straightforward — but there is one recurring local constraint.

Overhead branches. This is a city that takes its street trees seriously, and mature canopy over an older residential street or a driveway is common. Our truck needs roughly twenty-two feet of clear height to raise its bed. On a tile job with multiple swaps, that has to work every time, not once — so it is worth confirming at booking.

Elsewhere in the area:

• Newer Visalia subdivisions — generous driveways, straightforward placement.
• Older streets in Farmersville, Lindsay, Exeter and downtown Hanford — tight lots and short drives; a 15 yard with a swap is often the workable shape.
• Rural and foothill properties — plenty of room, but watch grade, surface and overhead lines at the entrance.

Everywhere: boards go under the rails as standard, and a tear-off sheds an enormous quantity of nails. A magnet sweep of the drive and the street at the end is twenty minutes well spent, and it is the single most common complaint homeowners have about roofing work.