The phrase "3 side" describes the same efficient covering configuration as "3-sided" — covers providing timber appearance on three visible faces while leaving the fourth (hidden) face open against the mounting surface. This naming variation simply reflects common industry terminology rather than a different product configuration. The 3-side hollow specification delivers efficient, practical beam covering for renovation and upgrade projects.
Understanding the configuration helps in product selection. Three sides get complete treatment; one side mounts against existing structure. The hollow construction keeps weight manageable. The faux wood material provides authentic timber appearance. These characteristics combine to create a covering solution that transforms utilitarian structural elements into design features efficiently and affordably.
Configuration clarification
The 3-side specification serves specific installations:
One hidden face — typically against ceiling, soffit, or wall mounting
Two visible side faces — apparent from room viewing angles
One visible bottom or front face — the primary visible surface
Open fourth side — no material where not visible
This efficient configuration matches most common structural beam installations.
When 3-side covers apply
The covering approach suits specific renovation scenarios:
Joist and beam ceilings
Exposed structural framing in finished spaces:
- Basement joist ceilings
- Exposed beam constructions
- Structural member visibility requiring treatment
- Renovation aesthetic improvements
Joist and beam ceilings commonly use 3-side covers.
Steel beam applications
Steel structural members in need of treatment:
- Residential steel beam installations
- Commercial structural steel
- Mixed construction with steel elements
- Aesthetic upgrade requirements
Steel beams benefit from timber-look covering.
Mixed structural situations
Buildings with various structural elements:
- Older construction with visible framing
- Modern construction with exposed elements
- Addition integrations requiring consistency
- Mixed material structural systems
Mixed situations often need consistent covering treatment.
Renovation aesthetic upgrades
Projects requiring aesthetic improvements:
- Existing structural elements gaining character
- Renovation aesthetic standards
- Visual consistency requirements
- Timber appearance throughout space
Renovation upgrades frequently use 3-side covers.

Advantages of the 3-side approach
Several practical benefits make this specification efficient:
Material efficiency — three faces use less material than four-face construction
Weight reduction — hollow construction with three faces minimizes weight
Cost savings — reduced material translates to lower product cost
Installation ease — lighter weight simplifies handling and mounting
Adequate coverage — three visible faces receive complete treatment
Structural integrity — no modification of existing structural elements required
These advantages make 3-side covers practical for covering applications.
Specifications
3-side hollow cover characteristics:
| Profile | Approximate Inner Opening | Weight per Linear Foot |
|---|---|---|
| 4x4 | 3.5" × 3.5" | 1.0-1.5 lbs |
| 4x6 | 3.5" × 5.5" | 1.5-2.0 lbs |
| 6x6 | 5.5" × 5.5" | 2.0-2.5 lbs |
| 6x8 | 5.5" × 7.5" | 2.5-3.0 lbs |
| 8x8 | 7.5" × 7.5" | 3.0-4.0 lbs |
| 8x10 | 7.5" × 9.5" | 4.0-5.0 lbs |
Match cover dimensions to structural beam plus installation clearance.
Installation methodology
Standard 3-side cover installation:
Measurement and planning
- Verify structural beam dimensions
- Plan cover lengths and any cutting
- Stage materials near installation area
- Prepare mounting surfaces
Installation
- Apply adhesive to interior contact surfaces
- Position cover over structural beam
- Secure with mechanical fasteners through side faces
- Install temporary support during cure
Finishing
- Caulk joints at terminations
- Touch up finish as needed
- Remove temporary supports after cure
- Clean installation area
Standard installation process ensures reliable results.
Common structural beam types
3-side covers accommodate various structural configurations:
Dimensional lumber
Standard residential framing:
- 2x6, 2x8, 2x10, 2x12 typical sizes
- Visible in basement and ceiling applications
- Easy measurement and specification
- Common covering application
Dimensional lumber is the most common covered beam type.
Engineered lumber
Modern structural products:
- LVL (Laminated Veneer Lumber)
- PSL (Parallel Strand Lumber)
- Glulam (Glued Laminated Timber)
- Standard engineered specifications
Engineered lumber accepts 3-side covering.
Steel beams
Structural steel in various applications:
- W-series wide flange beams
- S-series standard I-beams
- HSS (Hollow Structural Sections)
- Standard structural steel shapes
Steel beams need precise measurement before covering.
Finish options
3-side covers accept standard beam finishes:
Natural timber stains
Traditional appearance:
- Various stain colors
- Highlighted grain patterns
- Natural wood character
- Refined or rustic treatments
Natural stains emphasize timber aesthetics.
Painted finishes
Contemporary appearance:
- White painted beams
- Gray modern finishes
- Custom color applications
- Two-tone treatments
Painted finishes support contemporary aesthetics.
Specialty finishes
Project-specific treatments:
- Weathered appearances
- Distressed character
- Whitewash treatments
- Custom matched finishes
Specialty finishes enable distinctive character.
Profile considerations
Cover profile affects covering results:
Compact profiles for minimal change
Smaller covers for subtle treatment:
- 4x4, 4x6 profiles
- Subtle timber addition
- Minimal visual change
- Modest renovation intentions
Smaller profiles serve modest covering needs.
Standard profiles for typical coverage
Medium covers for standard treatment:
- 6x6, 6x8 profiles
- Balanced beam appearance
- Standard covering effect
- Most common specifications
Standard profiles serve typical covering requirements.
Larger profiles for substantial change
Bigger covers for significant upgrade:
- 8x8, 8x10 profiles
- Substantial beam appearance
- Significant visual upgrade
- Bold covering results
Larger profiles serve bold covering intentions.
Cost analysis
3-side hollow cover investment:
Material cost — $40-80 per linear foot for standard finishes
Premium textures — add $15-30 per linear foot for high-fidelity treatments
Installation cost — $60-120 per beam for professional installation
Project examples:
- Single beam covering: $400-1,200 complete
- Multiple beam covering (4-6 beams): $2,000-5,500 complete
- Comprehensive covering project: $4,500-12,000 complete
Investment reflects efficient 3-side construction.
When 3-side is appropriate
This specification serves projects where:
Three faces visible — structural beam configuration matches covering approach
Material efficiency valued — cost and weight considerations matter
Structural integrity preserved — no modification of structural elements needed
Standard configurations involved — typical structural beam scenarios
Adequate treatment achievable — three-face appearance sufficient for design
For these situations, 3-side covers deliver appropriate results.
When full coverage is needed
Some applications require complete four-face covering:
Freestanding beams — beams with all four faces visible from room
Complete encapsulation needed — situations requiring total structural coverage
All-angle visibility — beams viewed from multiple directions
Complete protection required — applications needing full structural encapsulation
Specific aesthetic needs — designs requiring solid beam appearance from any angle
For these situations, full 4-sided covers address the requirements.
Practical beam covering
3 side hollow faux wood PU beam covers provide practical covering solutions for the most common structural beam configurations. The combination of three-face treatment, hollow construction, and renovation-appropriate installation makes this specification appropriate for basement renovations, steel beam covering, engineered lumber treatment, and structural element upgrades. When projects require covering existing structural beams with efficient timber appearance treatment, 3-side hollow covers deliver appropriate results.
Specify 3-side hollow covers for structural beam covering projects requiring efficient three-face treatment with authentic timber appearance.
Technical References
ASTM standards cited in every specification
Test Data
Lab results from internal testing program
Updated 2026
Reviewed against current product specs