How to Attach Furring Strips to Concrete: The Ultimate Guide

If you‘re finishing a basement, garage, or renovating a space with concrete walls, installing furring strips is a great way to create a flat, smooth surface for drywall, tile, or other finishes. But how exactly do you securely fasten those furring strips to the solid concrete surface?

In this comprehensive guide, I‘ll draw on my 10 years of experience as a licensed contractor to walk you through the entire process of attaching furring strips to concrete. You‘ll learn:

• The best materials and methods for preparing concrete
• Pros and cons of various adhesives and mechanical fasteners
• Step-by-step instructions for proper installation
• Helpful tips to ensure your furring strips stay securely bonded

Let‘s start with the basics.

What Are Furring Strips?

Furring strips are long, narrow strips of wood or metal that are installed on walls and ceilings to serve as a base for finishes and provide space for insulation. They create a solid, level surface for attaching drywall, acoustic tiles, wood panels, plaster, and more.

Common Uses for Furring Strips

Some of the most popular uses for furring strips include:

• Leveling out uneven concrete or masonry walls
• Spacing walls away from cold concrete foundations for insulation
• Building out framing to allow for thicker insulation
• Providing reinforcement for tile backerboard installation
• Covering and smoothing damaged walls with a new surface

Why Use Furring Strips on Concrete?

Attaching furring strips to interior concrete walls or foundations offers many benefits:

• Levels out irregularities in poured concrete surfaces
• Creates continuous fastening surface for drywall or other finishes
• Provides space for insulation that improves energy efficiency
• Allows wall finishes to stand away from damp concrete
• Offers sound-dampening qualities when spaced out from wall
• Reduces condensation problems with air circulation behind strips

Additionally, a 2018 study by the National Association of Home Builders found that using furring strips to create an insulated cavity on basement foundations can reduce energy costs by up to 25%.

Preparing Concrete Prior to Attaching Furring

Achieving a strong, long-lasting bond when attaching furring strips begins with proper concrete preparation:

Cleaning

Start by thoroughly cleaning the concrete to remove any dirt, dust, oil, existing paints/coatings, efflorescence, or other surface debris. Here are some effective cleaning methods:

• Pressure washing with a commercial grade pressure washer
• Scrubbing with a concrete degreaser and stiff brush
• Sweeping or vacuuming away concrete dust and loose particles

Proper PPE like eye protection, gloves, and N-95 respirator should be worn during cleaning.

Etching the Surface

For best adhesion, the concrete should be mildly etched after cleaning to roughen the surface and remove any remaining efflorescence or laitance. This can be done by:

• Applying muriatic acid as an etching solution
• Grinding the surface lightly with a diamond attachment on an angle grinder
• Sandblasting for a deeper etch

Etching opens concrete pores, exposes aggregate, and gives adhesive and fasteners something to grip onto.

Drying

Before applying any adhesives, the concrete must be completely dry. Allow at least 24 hours drying time after pressure washing or etching before continuing with furring strip installation.

Choosing the Right Construction Adhesive

Using the appropriate adhesive is critical for creating a strong, long-lasting bond between furring strips and concrete. Here are some top options:

Polyurethane Construction Adhesive

Polyurethane formulas like PL Premium and Loctite Power Grab are ideal for concrete because they bond incredibly well to most common building materials. Polyurethane adhesives expand slightly while curing to fill gaps, making them perfect for rough concrete surfaces. I recommend these types for most furring strip applications.

Epoxy

Two-part epoxy adhesives create an extremely strong permanent bond. Epoxy can be used even on damp surfaces, making it a good choice for exterior concrete foundations. It requires precise mixing and only has a short working time before hardening.

Acrylic or Latex-Based Adhesive

General-purpose latex or acrylic construction adhesives provide an affordable option for attaching furring strips to dry concrete. Look for a concrete-bonding acrylic formula. Caution: Latex adhesives do not fill gaps as well polyurethane.

Regardless of type, always check that the adhesive is specifically made for bonding wood and concrete. Hardware stores carry many types that claim to bond everything, but the all-purpose products often don‘t work well in this application.

Mechanical Fastener Options for Concrete

In addition to construction adhesive, furring strips must be mechanically fastened to concrete for maximum strength. Here are some of the best options:

Tapcon Concrete Screws

Tapcon screws have hardened threads designed to grip into concrete substrata. Just be sure to pre-drill clearance holes with a masonry bit before installing. Use a hammer drill on any reinforced concrete. Tapcons require no anchors or sleeves, making them quicker to install than many alternatives.

Concrete Nails

While nails alone do not provide the holding power of screws, hardened concrete nails are an inexpensive option for attaching furring strips. Look for nail sizes between 16d and 60d. Pre-drilling is not required, but nails should be driven flush with the furring strip to prevent pull-through. Minimum length is 1.5 inches.

Powder-Actuated Nails

A powder-actuated tool uses a powder charge to drive hardened nails into concrete with extreme force. This creates superior holding power but requires special operator training and safety equipment. Hilti and Ramset are leading brands for powder-actuated concrete nails.

Wedge Anchors

Wedge anchors are inserted into pre-drilled concrete holes, then tapped until the sleeve expands, creating strong anchoring force parallel to the surface. They are more time-consuming to install than tapcons but allow for heavy-duty applications.

Step-by-Step Installation Guide

Here is a step-by-step guide to attaching furring strips to concrete correctly:

1. Plan Layout

• Mark furring strip locations on the wall spaced 16-24” apart

• Double up furring strips at corners and wall ends

2. Cut Furring Strips

• Use pressure-treated lumber for moisture resistance

• Wear PPE – eye protection, gloves, N-95 mask

3. Prepare Concrete

• Clean, etch, and allow to dry as discussed above

4. Pre-Drill Holes (if needed)

• For tapcons, wedge anchors, or fasteners over 3/16” diameter

• Use rotary hammer drill with carbide-tipped masonry bit

5. Apply Construction Adhesive

• Use 1⁄4” bead of polyurethane or epoxy adhesive along length

• Ensure continuous coverage across entire back surface

6. Position Furring Strips

• Press and align furring strips with layout marks

• Use temporary nails or braces to hold in place

7. Install Fasteners

• Drive tapcons or nails until flush with furring strip face

• Do not overdrive as this will reduce holding strength

8. Allow Adhesive to Cure

• Most adhesives reach full strength at 24-48 hours

• Avoid load on furring strips during this time

9. Install Finishes

• Once adhesive has cured, finishes like drywall can be installed

• Stagger seams between drywall sheets for added strength

And that covers the entire process! Follow these guidelines and your furring strips will remain firmly bonded to the concrete for years of trouble-free performance.

Helpful Tips for Proper Installation

Here are some additional tips to ensure your furring strips are securely attached:

• Use shims between furring strips to maintain consistent spacing if needed

• Avoid end-joint overlaps by spacing rows at least 24” apart

• Stagger end joints in adjacent rows for strength

• Check level and plumb often, use shims to correct furring alignment

• Drive fasteners straight and flush, do not overdrive screws

• Clean dust from concrete drilling before applying adhesive

• Clamp furring strips during initial adhesive cure if needed

Controlling Moisture and Condensation

Since furring creates an air gap on foundations, managing moisture is also important:

• Apply vapor barrier paint to interior side of concrete prior to installing furring

• Choose furring strips made of pressure-treated lumber for moisture resistance

• Include a vapor retarder on the warm-in-winter side of insulation

• Allow space behind strips for air circulation to evaporate moisture

• Use closed-cell spray foam insulation as it resists moisture absorption

• Monitor humidity and use dehumidifier if interior levels are consistently above 50%

Advantages and Disadvantages of Fastening Methods

There are pros and cons to each furring strip attachment method:

Construction Adhesive

Pros:

• Bonds well despite gaps
• Quick, easy application

Cons:

• Permanent, not adjustable
• Concrete requires etching/prep

Tapcon Screws

Pros:

• Extremely secure hold
• Allow repositioning

Cons:

• More time consuming
• Concrete must be pre-drilled

Powder-Actuated Fasteners

Pros:

• Most rigid attachment
• Minimal drilling required

Cons:

• Special tools required
• Safety training needed

Wedge Anchors

Pros:

• Heavy duty strength
• Does not require sleeves

Cons:

• Slower installation
• More precision needed

In many cases, a combination of adhesive and mechanical anchors will provide the strongest bond. I recommend using both adhesives and tapcon screws or powder-actuated nails whenever possible.

Safety Tips for Working With Concrete

It’s crucial to keep safety top of mind when taking on concrete projects:

• Wear proper PPE at all times – gloves, goggles, N-95 respiratory protection

• Use extreme caution when handling muriatic acid or other dangerous chemicals

• Drill concrete with sharp masonry bits to minimize dust

• Follow all manufacturer instructions for powder-actuated tools

• Prevent falls by maintaining secure footings and using ladders safely

• Work cautiously to avoid contact with eyes or skin when cutting materials

• Support heavy furring strips securely until they can be properly fastened

Adhering to best practices during transport, prep, drilling, cutting, and installation will help ensure you complete your project incident-free.

And there you have it – everything you need to know to securely attach furring strips to concrete. Let me know if you have any other questions! I‘m always happy to help a fellow DIYer.