100% money-backBook a walkthrough
Construction glossary · Wood framing

What is bottom platein construction?

A bottom plate, also called a sole plate, is the horizontal framing member at the base of a stud wall that the studs sit on and that anchors the wall to the floor or slab. Where the wall sits on a concrete slab on grade, the bottom plate must be pressure treated (PT) because it contacts concrete and is exposed to moisture.

Book a walkthrough Get a Free Takeoff

Free 30-minute walkthrough on your own drawings. No card.

Updated June 2026 · Reviewed by the Ruh construction team

Plies Single memberTakeoff 1 LF per LF of wallAt slab Pressure-treated req'dAlso called Sole plate

Bottom plate on subfloor

Stud (toe-nailed)Bottom plate (2x4)Subfloor / slab below
The definition

Bottom plate (sole plate), explained.

The bottom plate, or sole plate, is the bottom horizontal member of a stud wall. It is the same width as the studs, 2x4 or 2x6, and gives the studs a continuous nailing base while transferring wall loads down to the floor framing or foundation. On a wood subfloor the bottom plate is standard SPF lumber. On a concrete slab on grade, or any framing in direct contact with concrete or masonry, the plate in contact with the concrete must be naturally durable or preservative treated lumber, so framers use pressure treated stock there. PT plate is anchored to the slab with anchor bolts or approved fasteners, and a sill sealer or capillary break is often run under it. In takeoff you split the bottom plate count into standard material for walls on wood floors and PT material for walls bearing on slab. The bottom plate runs the full length of each wall, single course, with openings for doors cut out after the wall is stood and aligned.

How it is measured

Total the linear feet of each wall off the framing plan, single course, since the bottom plate is one member. Separate the runs that sit on a concrete slab on grade, which must be pressure treated, from runs on a wood subfloor, which take standard lumber. Read the foundation plan and wall sections to find where walls land on slab versus framed floor. Convert linear feet to pieces at your stock length and round up, keeping PT and standard quantities separate so they price correctly. Door openings are not deducted in rough takeoff because the plate is run through and cut out later. Report linear feet and piece count for each material type.

Worked example

A worked Bottom plate (sole plate) example.

Worked example

Say a building has 160 lf of total bottom plate, of which 100 lf of wall sits on a slab on grade and 60 lf sits on a wood subfloor, both 2x4. The 100 lf on slab is pressure treated; in 16 ft stock that is 100 / 16 = 6.25, round to 7 pieces at an illustrative PT price of $21 each = $147. Wait on the round figure: take a cleaner cut, 10 PT pieces for the slab runs at $21 = $210, and 6 standard pieces for the wood-floor runs at $11 = $66. Total bottom plate material: $210 + $66 = $276, US market illustrative pricing. Keeping PT separate matters because treated stock costs roughly double the standard plate here.

How Ruh handles it

How Ruh handles Bottom plate (sole plate).

100%

Try Ruh on a real bid. 100% money-back guarantee if you are not satisfied.*

*Scoped delivery, terms apply. Read the guarantee terms

Start with a walkthrough

Bottom plate (sole plate): frequently asked questions

What is the difference between a bottom plate and a sole plate?+

They are the same member. Bottom plate and sole plate both refer to the horizontal 2x member at the base of a stud wall. Some crews say mudsill, but that term specifically means the plate bolted to the top of the foundation, which is a sill plate.

When does the bottom plate have to be pressure treated?+

Whenever the plate is in direct contact with concrete or masonry, including walls on a slab on grade, the lumber must be naturally durable or preservative treated. Plates on a wood subfloor above grade can be standard SPF lumber.

Do I deduct door openings from the bottom plate takeoff?+

Not in rough takeoff. The plate is typically run continuous through door openings so the wall stays straight while it is stood and braced, then the plate is cut out at the doors afterward. Quantify the full wall length.

Still measuring by hand? Your next takeoff can run while you review this one.

See it on your plans

Related terms

Sill plateJack stud (trimmer)Top plateStudFire blockingSubfloorNominal vs actual lumber dimensions

Keep going: read the full guide or explore framing estimating software.

The Wood framing estimating cheat sheet
Every unit, waste factor, and conversion on one page. Free PDF.
Previous term
Blocking
Next term
Cripple stud

Figures on this page are illustrative. Construction estimates depend on project-specific conditions, source documents, market pricing, and professional judgment. Ruh's AI assists the estimator and does not replace professional review: your team reviews, validates, and approves every estimate, bid, and pricing decision.

100% money-back guarantee

Try Ruh on a bid you are pricing now.

Put your next takeoff on Ruh.