CTI Movement Joints & Expansion Joints 2

Question 1

What material should be installed inside a movement joint before applying sealant to control joint depth and prevent three-sided adhesion?

Accepted Answer

Polyethylene foam backer rod

Answer

Thinset mortar

Answer

Sanded grout

Answer

Roofing felt

Question 2

For exterior tile installations, what is the maximum recommended spacing between movement joints per TCNA EJ171?

Accepted Answer

8–12 feet in each direction

Answer

16–20 feet in each direction

Answer

20–25 feet in each direction

Answer

25–30 feet in each direction

Question 3

A CTI inspector observes a 30×30 foot interior tiled floor with no movement joints anywhere. What deficiency does this represent?

Accepted Answer

A code and standards violation with risk of cracking or tile failure

Answer

A cosmetic issue only requiring monitoring

Answer

Acceptable practice if large-format tiles were used

Answer

Normal for single-family residential floors

Question 4

Which material must NEVER be used to fill or close a movement joint in a tile installation?

Accepted Answer

Portland cement grout or mortar

Answer

Color-matched silicone caulk

Answer

Flexible polyurethane sealant

Answer

Urethane joint sealant

Question 5

What is the purpose of a 'soft joint' (movement joint) installed at changes in plane, such as where a floor meets a wall?

Accepted Answer

To accommodate differential movement between horizontal and vertical tile planes

Answer

To improve the decorative transition between surfaces

Answer

To reduce the amount of grout needed at corners

Answer

To allow easier removal of tiles during future renovations

Question 6

On column bases in a tiled area, where should a CTI inspector verify that movement joints are present?

Accepted Answer

On all four sides of each column base

Answer

Only on the side facing the primary traffic direction

Answer

On the north and south sides only

Answer

Only where the column exceeds 12 inches in diameter

Question 7

What is the recommended depth-to-width ratio for sealant within a properly designed movement joint?

Accepted Answer

Depth is half the width (width:depth = 2:1)

Answer

Depth equals width (1:1)

Answer

Depth is twice the width (2:1)

Answer

Depth is three times the width (3:1)