How to Install Turf Underlayment on Concrete

Drainage Pad vs. Solid Foam: Which Is Better?

Start with the exposure conditions.

For an outdoor slab, pet area, or frequently washed surface, drainage usually deserves priority. The system needs to let moisture pass through the turf and then move toward a drain or edge.

For covered indoor applications where water exposure is minimal, cushioning and stability may matter more than open drainage. Solid or closed-cell padding can therefore be appropriate, provided it is compatible with the turf and installation method.

Neither type should be assumed to stay in place automatically. Correct joint treatment and fixing are important because movement in the padding can eventually become visible through the turf above.

How to Install Turf Underlayment on Concrete

Prepare and Check the Concrete Base

Start with the existing slab clean and free of loose debris, and patch cracks or spalled areas. The padding can only perform on a stable base, so check for undulations. Pay special attention to drainage: find the low spots where water pools, because liquid sitting beneath the grass leads to mold and odor later.

Lay, Join, and Secure the Underlay

Lay the underlay according to the manufacturer’s recommended joint and fixing method, keeping adjoining pieces flat and avoiding overlaps or raised edges that could become visible through the turf. Use fixing methods compatible with the pad, concrete base, turf system, and expected use.

A detail we often see underestimated is the joint between two pieces of padding. Customers naturally spend more time comparing the turf itself, but problems that appear months later can start in this hidden layer. If padding rolls are poorly aligned, insufficiently secured, or allowed to move independently, repeated foot traffic can gradually create visible joint lines, wrinkles, or uneven areas in the turf above.

This becomes more important where temperatures vary significantly between seasons because the materials in the system need enough flexibility to accommodate movement. For landscape applications, we focus on keeping the underlay flat and stable so the finished lawn remains smooth and comfortable. For football and other high-use sports surfaces, fixing and joint stability matter even more because the padding must remain consistent under repeated running, turning, and impact.

Saving a small amount on the underlay or its installation can therefore create a much larger repair job later. Before laying the turf, check the surface again for loose joints, ridges, or movement, and make sure fixing materials do not block the intended drainage path.