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Replacing an old toilet

Swapping an older Alhambra toilet means measuring rough-in, choosing a bowl shape and checking the flange.

Mon–Sat · houses, duplexes and units in Alhambra

Updated · 3 min read

If you read one thing

Measure from the wall to the center of the floor bolts to find the rough-in, usually 12 inches. Pick round or elongated to fit your space, choose a WaterSense model, and check the flange when the old toilet comes up.

In this guide
  1. Measure the rough-in
  2. Round or elongated
  3. Water use
  4. The install
  5. Alhambra homeowner questions

Measure the rough-in

Measure from the finished wall behind the toilet to the center of the bolts at the base. Most houses use 12 inches. Some older bathrooms use 10 or 14.

Alhambra has many prewar houses; close to a quarter were built before 1940, per Census Reporter. Older bathrooms are more likely to have an unusual rough-in.

Measure wall to bolts then Check bowl clearance then Pick a WaterSense model then Lift old toilet then Inspect flange and set new1Measure wall to bolts2Check bowl clearance3Pick a WaterSense model4Lift old toilet5Inspect flange and set new
The steps to a clean toilet swap.

Round or elongated

Elongated bowls are more comfortable but stick out a couple of inches further. In a narrow bungalow bathroom, a round bowl may be the better fit.

Round bowl: Shorter front to back; Good for tight baths; Often a lower profile. Elongated bowl: Longer seat; More comfortable; Needs more clearanceRound bowl• Shorter front to back• Good for tight baths• Often a lower profileElongated bowl• Longer seat• More comfortable• Needs more clearance
Bowl shape choices.

Water use

EPA's WaterSense toilet page says WaterSense-labeled models use 1.28 gallons per flush or less, while older toilets can use as much as 6.

A modern WaterSense toilet with a wide flush valve clears waste well, even in older drain lines.

The install

The water is shut off, the old toilet drained and removed, and the flange checked. A new wax or foam seal and closet bolts go on, the bowl is set and bolted, and the tank and supply line connected.

Hard water at about 240 ppm in Alhambra, per the city report, is a good reason to replace the supply line and stop valve at the same time.

Alhambra homeowner questions

Can I put a 12-inch toilet on a 10-inch rough-in?

No, it will not fit against the wall. Use a toilet made for 10-inch rough-in.

Should I pick a comfort height bowl?

Taller bowls are easier for many adults. Shorter users and children may prefer standard height.

What happens to the old toilet?

Ask about removal when you text for a quote, or set it out for your city's bulky item pickup.