Tie rod hole filling permanently
Case Study : Tie rod hole filling with Polyurethane foam spray sealant , reduce costs drastically, no leakages too. Exercise done & implemented at a reputed Construction company in Mumbai
What are Tie Rod Holes
During the construction small metal rods, called tie rods, are inserted into the concrete form in order to hold the inner and outer forms together, and provide the structure with which the concrete can be poured. … After construction, they are usually either removed entirely, leaving a hole.
Tie Rod Hole packing is a commonly observed action during the time of finishing process of any construction. Most constructions will have tie rod enforcement holes equally spaced out on the walls. These can be observed as small irregularities on the surface. Over time, these holes need to be sealed. This is to prevent any chances of future leakages or seepage through the wall.
Conventional methods for Tie Rod Hole filling.
include ‘Swell Plugs’ , PU Injection grouting, cement grouting and etc.
Problems with conventiional methods
- labour intensive – pu injection grouting/ cement grouting : high labour cost
- Time consuming
- Difficult to access from outside for high rise buildings- expensive scaffolding/ crane required.
- Swell plugs are expensive and also needs access from outisde.
- effective waterproofing of tie rod holes is still uncertain.
Costing of Cement Grouting method
Considering the length of the hole to be 500 mm, with a diameter of up to 50 mm
- 1 bag of 25 kgs (can fill up to 75 holes) = INR 450/-, material cost = Rs 6 per hole
Labor cost: 2 labourers will grout 50 holes per day. Let us assume they are paid INR 750/- each. Labour cost per hole= Rs. 30.
- Cement grouting cost per tie rod hole= Rs 36
This process is tedious, labor-intensive and for high rise towers inaccessible/unsafe for manual grouting
PU foam Spray costing:
Material Cost:
- One 750 ml foam can, filled (can fill up to 66 holes of 20 mm diameter * 450 mm length), Approx Cost of one 750 ml can =450 + GST.
- Per hole material cost = PU foam + Pu cleaner + Pu Gun = 6.8+.5+.5 = Rs 7.8
Labor Cost: One worker can fill approx 250 holes in a day. Per hole labor cost = Rs. 4 (Rs. 1000 per day labor cost)
- Total cost =Rs. 11.8 per hole
Tie Rod Hole Sealing with Polyurethane Expanding Foam Spray
Expanding polyurethane Foam Spray Sealant Method – Using Supex 100 PUF Gun Grade
Application Procedure:
- Clean the Tie rod holes with local water spray.
- Apply Supex 100 PU foam using Gun.
- Sealant will expand and cure in 15 to 30 minutes.
- Cut excess foam coming out of hole using knife.
- Water Test : spray water under pressure from one end to check if it leaks to the other end.
- Sanding, putty, plastering, painting can be done as we do with cement grouting
Benefits of PU Foam Spray vs. Cement Grouting
PU foam spray offers clear advantages over traditional cement grouting. First, it saves money. You save Rs 24.2 per hole, which means a 45% reduction in cost. Additionally, productivity improves dramatically—by 500%. Workers finish jobs much faster.
Moreover, PU foam ensures a leak-free seal. This provides better reliability and long-term performance. The process is also safer, with no heavy mixing or dust. Finally, it delivers improved aesthetics. The finish looks cleaner and smoother.
Other Uses of Polyurethane Expanding Foam Spray
One-component spray polyurethane foam (PUF) starts as a frothy liquid. It expands quickly. Then, it moisture-cures into solid foam. This creates excellent insulation and sealant. Both fire-rated and regular versions come in convenient aerosol cans.
Here are common applications:
- Fixing window and door frames securely.
- Sealing split AC holes for cables.
- Isolating transition joints between walls and RCC beams.
- Sealing openings in roof construction, especially metal roofs.
- Improving thermal insulation in cooling systems.
- Filling free spaces, cracks, gaps, and pipe penetrations.
- Sealing duct shafts effectively.
- Creating models, design patterns for film production and interior designers.
- Sealing gaps between cables and wires in electric panels or process plants.
- Sealing gaps between cables and wires in the solar industry.
PU foam spray is versatile. It works well in many construction and creative projects.
One Response
Supex 100 PUF gun grade