The inventory is the work
Ask anybody what in their house is tall, heavy and standing on its own and you get a shrug and a vague gesture at a bookcase. Ask them to write down six items with a width, a depth, a height and a loaded weight and something changes, because the exercise forces a walk through every room with a tape measure. That walk is most of the value here. The material list that comes out the other end is short — a few dozen feet of strapping and a box of fixings — and it was never the obstacle.
Loaded weight is the field people get wrong. A bookcase is not the weight of the bookcase. A shelf of books is heavy, a shop shelf of paint and hardware is heavier, and a run of upper cabinets full of crockery is heavier again. Estimate what it weighs full, because that is the mass involved.
What the strap length is measuring
One run here is measured across the width, down both sides, and out to a tail at each end for the turn and the fixing. So a 30 inch wide bookcase 12 inches deep with a 6 inch tail gives a run of 66 inches, and two runs on three of them is 33 feet before anything else on the list. That model is a plain geometric one and it is stated so you can check it against whatever you are actually installing — a product with its own geometry gives you its own lengths, and this arithmetic just tells you how much material to have on the bench.
| Field | What it is | Where the real answer comes from |
|---|---|---|
| Strap runs per item | A count you choose | The restraint manufacturer and your building department |
| Tail at each end | A fabrication allowance | Whatever the fixing detail actually needs |
| Fixing points per end | Blank until you fill it in | The manufacturer and the adopted rule — never a calculator |
| Framing spacing | A reporting convenience | A detector on the actual wall, every time |
The ordering is a sort, not a judgement
The work order on the results is height divided by depth, largest first. A 84 inch bookcase on 12 inches of depth comes out at 7 to 1; a 48 inch chest of drawers 18 inches deep comes out at 2.7. That ratio is pure geometry and it is a reasonable way to decide what to tackle first when the list is longer than the afternoon you have.
What it is not is an assessment. It knows nothing about what is on the shelves, whether the mass is at the top or the bottom, what the floor is, what the wall is made of, what the fixing lands in, or what the ground under the house does. Two items with identical ratios can be entirely different problems. Treat it as a queue and nothing more, and take the actual question of what needs restraining, and how, to your building department and to the product manufacturer.
The water heater is not a furniture job
It appears on the default list because it appears on everybody list, and it is the one item on it that is not a weekend task with a strap. A storage water heater has water connections, and either gas and a flue or an electrical supply. An appliance that moves on its base can part a connection, and what happens next depends on which connection it was. In many jurisdictions the restraint detail for a water heater is prescribed, the work is permitted, and it is inspected.
So the honest advice is the same as everywhere else on this page: get the detail from the building department and the appliance manufacturer before buying anything, and use a licensed plumber where gas is involved. This page gives you the strap length and nothing else.
What is deliberately missing
Any fixing specification, any anchor rating, any load, any capacity, any statement about what a wall will hold, and any figure for what shaking a given area should be prepared for. Those are engineering and regulatory questions about specific assemblies in specific places, they differ enormously across the country, and a number produced by arithmetic here would be worse than no number at all. Your building department, the restraint manufacturer and your state emergency management agency are the sources. Earthquake insurance is normally a separate policy from a homeowner one, which is a conversation with your insurer. Background reading sits in the earthquake and flood guide, and the household side of preparation is in the family emergency plan.
Questions people ask
How many straps does a water heater need and where do they go?
This page will not tell you, and that is not evasion. Water heater restraint is prescribed in some jurisdictions and not in others, the detail differs, the work is frequently permitted and inspected, and the appliance manufacturer has its own instructions that interact with all of it. A storage heater also has water connections and either gas and a flue or an electrical supply, and an appliance that shifts can part one of them. Ask your building department and the manufacturer, and use a licensed plumber where gas is involved. The calculator gives you material lengths only.
What fixings should I use into a wall?
Not a question a takeoff can answer. What holds depends on what the wall is, what is behind the finish, where the framing actually falls, what the product is rated for and what the adopted rule requires, and none of those are knowable from a dimension. The fixing-points field starts at zero for that reason and only counts what you tell it. A restraint that pulls out of drywall has restrained nothing, which is why the answer comes from the product manufacturer and your building department rather than from arithmetic.
What does the ratio in the work order mean?
It is height divided by depth, sorted with the tallest and narrowest first. A 7 foot bookcase a foot deep scores 7 to 1; a chest of drawers half that height and half again as deep scores under 3. It is geometry and it is offered as a queue for deciding what to do first, not as an assessment of risk. It knows nothing about where the mass sits, what is on the shelves, what the floor and wall are, or what the ground does. Two items with the same ratio can be completely different problems.
Should I include the weight of what is on the shelves?
Yes, and it usually dominates. A bookcase weighs a fraction of what a bookcase full of books weighs, and a shop shelf loaded with paint and hardware is heavier again. The weight column is there to give you a total that reflects reality rather than an empty-furniture number, and to make the scale of the list visible. It is your estimate and the page does nothing with it beyond totalling it — no load, no capacity and no rating is derived from it anywhere.
Is 16 inch framing spacing a safe assumption?
No, and the field exists so that you can change it rather than so you can rely on it. Spacing varies with the age of the building, the wall, and what the framer did that day, and remodelled walls are frequently irregular. Use a detector on the actual wall and confirm what you find, ideally by making a small hole where it will be covered. The spacing here only produces a rough count of how many members sit behind an item, and that count is a planning convenience, not a location.