Figuring square footage for paying installer

Old 11-28-18, 08:30 AM
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Figuring square footage for paying installer

When a siding installer charges "per square", Where is that number taken from? Is that the actual number of squares that was installed? Are windows and doors subtracted, or is it the total "box"? Or is it the number of squares of siding that was ordered (higher number to factor in waste)?

My contract just says the "per square" rate, not the actual number of squares it's going to be based on. I just want to make sure it ends up being fair for both of us.
(I'll be adding this clarification to the contract after figuring this out).

Thanks for everyone's help. I'm learning a lot from this experience and everyone here.
Old 11-28-18, 08:50 AM
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It kind of depends on the size of the windows and doors and how much waste there is going to be. For example, gable ends create a LOT of waste so you cant measure them exactly... you need to add maybe 20% waste on gable sq ft.. Other than that, you can't go wrong if you figure the exact siding area including doors and windows... then assume that anything you "save" by going around doors and windows will be used up in unavoidable waste.

But if your house has a lot of large windows, that is obviously overkill. So it is often good to measure up door and window area and see how it compares to the overall Sq ft as a percentage. If the house (including doors and windows) measures 10 squares... and your doors and windows equal .5 to 1 sq... that is 5 -10% which is a reasonable amount to include in the estimate to account for waste.

You also need to keep in mind that siding is usually ordered in 2 sq increments, so you might not find a guy who is willing to give you a bid for 11 sq... since he has to order 12. And the installer usually keeps any funds from "returns" once the job is complete. So most installers will figure it like I mentioned, then they try to be as efficient as possible so that they might have just a little bit to return at the end of a job... usually a partial box of misc siding and accessories.

This sort of overrun is normal because you can't make money if you figure too close and run short... when that happens, the supplies either come out of your pocket, or you have to tell the customer you are short and then there is a big fight where the customer invariably thinks the installer sucks or that they are getting screwed.
Old 11-28-18, 03:35 PM
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Additionally, getting multiple estimates from different contractors can help you discern what a good price is especially if different methods of estimating are used.
Old 12-08-18, 10:36 PM
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Typically measure the house exterior, figure the extra for gables. More windows and door take less siding but more trim and cutting. Double 4 siding wastes less then Cedar Impressions. If your measurements turn out to be just over a square, you could end up with just under two square extra that will end up in your crawl space or garage. Many places sell only by the full box. Like buying floor tile. There is also squeezing out every inch you can get but, you don't want every short scrap used on your siding. Usually nothing shorter then 2'.

Get at least two bids and trust who ever you go with.

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