Top 5 Foam Filler for Gap Filling
Foam fillers are widely used in construction to fill gaps, cracks, joints, and voids in walls, slabs, frames, and service penetrations. Expanding PU foam helps seal air leaks, improve insulation, and provide a durable fill in irregular spaces where traditional fillers cannot perform effectively.
Where Foam Fillers Are Used for Gap Filling
Gap filling foam is used across multiple construction and finishing works.
- Gaps between walls, slabs, and columns
- Cracks and voids in masonry and concrete
- Openings around pipes, cables, and ducts
- Gaps around doors, windows, and frames
Key Properties of a Good Gap Filling Foam
Not all foams perform the same on site.
- Controlled and uniform expansion
- Strong adhesion to common building materials
- Good thermal and acoustic insulation
- Easy cutting and finishing after curing
Companies Name
- Palco
- Bostik
- Soudal
- Sika
- Fosroc
1. Palco PU Foam
Palco PU Foam is commonly used for general construction gap filling.
- Strong adhesion to concrete, brick, wood, metal, and PVC
- Expands effectively to fill gaps and voids
- Provides thermal and sound insulation
- Easy to trim and finish after curing
2. Bostik PU Expanding Foam
Bostik PU Foam is suitable for sealing and filling construction gaps.
- Reliable expansion and gap filling performance
- Good bonding with most construction substrates
- Helps reduce air leakage and drafts
3. Soudal PU Gap Filling Foam
Soudal PU foam is widely used for professional gap filling applications.
- Stable expansion with good filling capacity
- Effective thermal and acoustic insulation
- Suitable for interior and exterior use
4. Sika Boom PU Foam
Sika Boom expanding foam is designed for construction sealing works.
- Uniform cell structure for consistent filling
- Good adhesion and durability
- Suitable for cracks, joints, and penetrations
5. Fosroc PU Expanding Foam
Fosroc PU foam is used for sealing and filling gaps in construction.
- Consistent expansion behaviour
- Improves airtightness and insulation
- Used in wall gaps, service openings, and voids
Common Site Mistakes to Avoid
Incorrect use reduces foam performance.
- Overfilling gaps causing excessive expansion
- Applying foam on dusty or dry surfaces
- Using high-expansion foam where controlled expansion is required
Frequently Asked Questions (FAQ)
1. Can foam filler be used for large gaps?
Yes, expanding PU foam is suitable for filling both small and large voids.
2. Is gap filling foam waterproof?
It resists moisture but should be protected with finishing layers.
3. Can cured foam be plastered or painted?
Yes, once fully cured, it can be cut, plastered, or painted.
4. Does foam provide insulation?
Yes, it offers thermal and acoustic insulation.
5. Is foam filler structural?
No, it is used for sealing and filling, not load-bearing purposes.
Raltro
Raltro is a construction knowledge platform focused on correct material usage and site best practices. By explaining the top foam fillers for gap filling and their proper applications, Raltro helps contractors and builders choose reliable sealing solutions that improve insulation, reduce air leakage, and deliver long-lasting construction performance.