Water-based underfloor heating is the smartest home-heating solution in Israel: even heat, no visible heating elements, and significant savings on electricity bills over the years. The foundation of every such system is SP 16×2 Red piping – SP Industries’ dedicated pipe for underfloor heating, manufactured to the strictest standards and backed by a 25-year warranty. This guide will explain everything — from choosing the right pipe to full installation rules.
Quick Summary
- Dedicated pipe: SP 16×2 Red only for underfloor heating
- Available coil lengths: 120 m, 240 m, 300 m
- Maximum operating pressure: 10 bar | Maximum temperature: 95°C
- The pipe is protected by an EVOH layer – prevents corrosion in metal fittings
- 25-year warranty from SP Industries
- The best SP prices on the market – see below
Why choose SP pipe for underfloor heating?
Not every PEX pipe is suitable for underfloor heating. SP heating pipe is manufactured with an EVOH layer (Ethylene Vinyl Alcohol) — a unique protective layer that prevents oxygen from entering the water. This is critical: oxygen in the water causes corrosion in all the metal components in the system (heat pump, manifolds, thermostats). Without EVOH, the factory warranty does not apply.
Pipe layer structure:
- Outer layer – cross-linked polyethylene
- Adhesive layer
- Core layer – aluminum
- Adhesive layer
- EVOH layer – oxygen barrier
- Inner layer – cross-linked polyethylene
The pipe comes in red (and white) and is suitable for temperatures up to 95°C and pressure up to 10 bar.
SP pipe coils for underfloor heating – SKUs and lengths
| Description | Coil length | SKU |
|---|---|---|
| SP 2×16 red pipe | 120 m | 77000133-00120-20 |
| SP 2×16 red pipe | 240 m | 77000133-00240-20 |
| SP 2×16 red pipe | 300 m | 77000133-00300-20 |
Which coil length should you choose?
120 m – suitable for a single room or a small area up to about 15 m².
240 m – for an average apartment with 2–3 rooms.
300 m – for large homes, villas, and commercial spaces.
Rule of thumb: for underfloor heating, pipes are spaced about 15 cm apart — roughly 6.5 m of pipe per m².
Mandatory installation rules according to SP Industries
Before installation:
- Plan the pipe layout and have it approved by a system engineer
- Prepare a thermal insulation layer beneath the piping
During installation:
- The supply is taken from the water manifold (recommended inside an SP manifold cabinet)
- Each pipe loop is connected directly from the manifold — no joints in the middle of the loop
- Distance between pipes: about 15 cm (according to the system design)
- No fittings may be installed under the flooring — only a continuous pipe with no breaks
After installation:
- Pressure testing is mandatory before pouring the concrete
- Test pressure: minimum 15 atmospheres, for a full hour
- Allowed pressure drop: up to 0.5 atm only
- After the test, the concrete can be poured and the floor can be tiled
Forbidden: fittings under the flooring
It is strictly forbidden to install connecting fittings (connectors, elbows, T-joints) within the heated flooring area. The entire pipe from manifold to manifold must be continuous with no joints whatsoever. A joint that fails under the floor = massive, very expensive damage to repair.
⚖️Water-based underfloor heating – pros and cons
✅Advantages
- •Even, pleasant heat rising from the floor upward – no cold spots
- •Savings of up to 50% on heating costs compared with an electric air conditioner
- •No visible heating elements – clean design
- •Complete silence – no fan noise
- •Works with heat pumps for maximum savings
- •25-year warranty with SP piping
❌Limitations
- •Higher initial installation cost than electric heating
- •Requires early planning before the concrete pour
- •Longer initial heat-up time (high thermal mass)
- •Fixing a fault under flooring is more complex
Despite the higher upfront cost, a water system pays for itself within 3–5 winters thanks to significantly lower operating costs.
🏆 The best price on the market for SP piping
All SP Industries underfloor heating products on our site come with the biggest discount you’ll find in Israel.
Found a lower price elsewhere? Contact us — and we’ll beat the price. We don’t lose a deal over price.
Frequently asked questions about water-based underfloor heating with SP
Can regular SP pipe be used for underfloor heating?
No. For underfloor heating, you must use only SP 16×2 Red pipe with an EVOH layer. Using a pipe without EVOH will cause corrosion in the metal fittings and void the warranty.
How many meters of pipe are needed per square meter?
On average, about 6.5–7 m of pipe per m² of heated area, depending on the spacing between pipes (10–15 cm). For a full 100 m² apartment — about 650–700 m of pipe in total.
What is the maximum temperature of the pipe?
SP pipe is rated up to 95°C. In practice, an underfloor heating system operates with water at 35–45°C — well below the pipe’s limit.
How many years of warranty?
25-year warranty from SP Industries — provided it is installed by a certified installer, with approved SP fittings, and a proper pressure test is carried out.
Is SP pipe suitable for direct concrete pouring?
Yes. SP cross-linked PEX and aluminum pipe eliminates thermal expansion (only 2.5 mm per meter compared with 15 mm in standard PEX), and is suitable for direct pouring without conduit.
Conclusion
Water-based underfloor heating with SP piping is the smartest investment for a warm, efficient, and comfortable home for many years to come. With a 25-year warranty, proven technical specifications, and the most reliable products on the Israeli market — there’s no competition. All SP heating products are available from us at the best price in Israel — and if you find a cheaper offer, we’ll beat it.