SUNPERL® perlite-cement screed is the lightest, fireproof, eco-friendly thermal barrier installed beneath hydronic underfloor heating in South African homes. Synergy designs, mixes and installs a 20 mm perlite layer from approximately R159 per m², stopping up to 30% of your underfloor heat from being lost downward into the slab and turning every kilowatt of your heat pump into comfort, not waste.
Book a Free Site Assessment See How It WorksSynergy Energy Solutions installs SUNPERL® perlite-cement floor insulation across South Africa from three branches: Centurion (Gauteng HQ), Cape Town (Western Cape) and Polokwane (Limpopo). All branches share one phone number, 010 601 6464. A standard 20 mm perlite-cement screed is installed from approximately R159 per square metre, stops up to 30% of underfloor heat from escaping downward into the slab, and is non-combustible Class 0 by classification. SAPVIA-aligned, ECA-affiliated, with 200+ underfloor heating projects delivered nationwide since 2010.
See how hydronic underfloor heating works, the system SUNPERL® perlite is designed to insulate. A dedicated perlite installation walk-through is coming soon.
Perlite floor insulation works by mixing SUNPERL® expanded volcanic perlite with 42.5N cement and a bonding liquid, then applying it as a 20 mm screed directly onto the concrete slab. Once cured for 10 to 14 days, the perlite layer becomes a load-bearing thermal break that stops heat from your hydronic underfloor heating pipes from being lost downward, directing nearly 100% of the heat your heat pump or boiler generates upward into your floor finish and living space, where you actually feel it.
Who this suits best: homeowners installing hydronic underfloor heating in a new build or major renovation, architects and developers specifying Green-Star-aligned multi-storey projects, builders who want a load-bearing screed that doesn't need reinforcing mesh, and anyone replacing combustible polystyrene boards with a fireproof, lifetime-stable mineral alternative. If you're retrofitting a finished home and don't want to lift floors, carbon fibre wall heating may suit you better, we install both and will recommend honestly.
The Synergy difference. Every perlite installation is project-engineered: we inspect the slab, calculate the required layer thickness against your pipe layout and floor build-up, mix SUNPERL® with 42.5N cement on site to the correct ratio, and hand off a cured, level, load-bearing substrate ready for your tiler or screeder. No premix bags, no shortcuts on cure time.
Natural, proven and engineered for South African conditions, perlite delivers measurable advantages over polystyrene boards, foam panels and bare screed. Six reasons it has become the default thermal break under hydronic underfloor heating in 200+ Synergy projects.
Directs nearly all generated heat upward into the floor surface, so your heat pump or boiler runs at lower water temperatures for the same comfort, immediate savings on every Eskom tariff. Stops up to 30% of underfloor heat from being lost downward into the slab.
As a volcanic mineral, perlite will not burn and emits no toxic fumes under fire, rated Class 0 by classification. A major safety advantage over petroleum-based EPS or XPS polystyrene boards, which are combustible.
At densities from 32 to 240 kg/m³, perlite reduces dead load on your slab while providing a stable, load-bearing substrate, ideal for multi-storey developments, retrofits and homes with heavy floor finishes such as natural stone.
An inert, non-toxic volcanic mineral with minimal mining and processing footprint. Ideal for homeowners and developers seeking sustainable materials that align with Green Star expectations and SANS energy-performance standards.
Perlite does not rot, decay, absorb water or attract vermin. Its thermal and structural integrity lasts as long as the building itself, no maintenance, no degradation, no replacement schedule.
Beyond floors, perlite can plaster walls and insulate concrete roof slabs, giving you an integrated, whole-home approach to energy-efficient insulation across floors, walls and ceilings for optimal year-round thermal performance.
Every SUNPERL® perlite floor insulation we install is built from five precision components, each chosen for performance under hydronic underfloor heating in South African conditions, from the volcanic mineral itself through to the cured, level screed your tiler hands off to.
The thermal heart of the system. Millions of glass-sealed air bubbles inside each granule give perlite its outstanding insulating value, 8 to 10 times more effective than ordinary plaster sand.
The binder that turns loose perlite into a stable, durable insulating screed. Combined correctly with SUNPERL®, it delivers the compressive strength needed to support tile, stone or wood finishes, without reinforcing mesh.
The often-skipped step that separates a long-life installation from a failed one. Synergy slushes bonding liquid both into the mix and onto the slab itself, locking the perlite layer permanently to the concrete.
The thermal break itself. Applied and screeded level across the slab, this is the layer that stops up to 30% of your underfloor heat from escaping downward into the ground.
The unglamorous component that makes everything else work: a proper cure. Synergy never short-cuts the 10 to 14 day window, that's what gives the screed the strength to hold underfloor heating pipes for the lifetime of the building.
We install only SUNPERL®-grade expanded perlite, mixed on site with 42.5N Portland cement to the ratio specified for hydronic underfloor heating substrates. Every job is hand-finished and cured for 10 to 14 days before any pipe is fastened.
| Specification | Synergy Standard |
|---|---|
| Insulation material | SUNPERL® expanded perlite (volcanic mineral) with 42.5N Portland cement |
| Thermal conductivity (loose fill) | 0.04 to 0.05 W/m·K |
| Thermal conductivity (cement screed) | 0.09 to 0.14 W/m·K |
| Density | 32 to 240 kg/m³ (lightweight) |
| Standard application thickness | 20 mm (scalable to project requirements) |
| Fire rating | Non-combustible, Class 0 (mineral-based) |
| Compressive strength | High, supports final floor finishes without added reinforcing mesh |
| Water absorption & decay | Inert, does not rot, decay or attract vermin |
| Curing time | 10 to 14 days before underfloor heating pipes can be fastened |
| Compatible with | Hydronic (water) underfloor heating, heat-pump-fed underfloor systems, electric underfloor heating mats |
| Downward heat loss prevented | Up to 30% versus an uninsulated concrete slab |
| Effectiveness vs plaster sand | 8 to 10× more effective at blocking downward heat loss (loose-fill k-value) |
| Standards & safety | Non-combustible Class 0 mineral; SANS 10400 fire-safety aligned; non-toxic and safe for residential use |
| Service life | Lifetime, does not rot, decay, compress or degrade thermally |
| Typical installed cost | From approximately R159/m² (20 mm layer, whole-home rate) |
Translation in plain English. Perlite is 8 to 10 times more effective at blocking downward heat loss than ordinary plaster sand (k-value 0.4 W/m·K), yet light enough that it barely adds to your building's structural load. That's why it has become the default thermal break under hydronic underfloor heating in most South African new-build and renovation projects.
Every floor insulation has a use case. Here's how SUNPERL® perlite-cement screed stacks up against the most common alternatives under hydronic underfloor heating in South African homes, honestly, including the rows where perlite is not the absolute winner on a single metric.
| Feature | SUNPERL® Perlite Screed | EPS Polystyrene | XPS Polystyrene | PIR / PUR Boards | No Insulation |
|---|---|---|---|---|---|
| Material origin | Natural volcanic mineral | Petroleum-derived | Petroleum-derived | Petrochemical foam | - |
| Thermal conductivity (k-value) | 0.09 to 0.14 W/m·K (screed) | 0.030 to 0.040 W/m·K | 0.025 to 0.035 W/m·K | 0.022 to 0.028 W/m·K | - (uninsulated slab) |
| Fire safety | Non-combustible, Class 0 | Combustible | Combustible | Combustible (some retardants) | N/A |
| Toxic-fume risk under fire | None, mineral-based | Yes (styrene) | Yes (styrene) | Yes (cyanide compounds) | N/A |
| Compressive strength | Load-bearing without mesh | Lower, mesh required | Moderate, mesh advised | Moderate, mesh advised | Slab only |
| Reinforcing mesh required | No | Yes | Yes (typically) | Yes (typically) | N/A |
| Top screed thickness needed | Thinner top screed permitted | Thicker top screed required | Thicker top screed required | Thicker top screed required | N/A |
| Long-term dimensional stability | Lifetime, will not compress | Can creep / compress | Better than EPS | Stable | N/A |
| Water absorption / decay | Inert, no rot, no vermin | Low absorption | Very low absorption | Low absorption | N/A |
| Weight on structure | 32 to 240 kg/m³ (light) | Lighter alone, heavier total floor build-up | Lighter alone, heavier total floor build-up | Lighter alone, heavier total floor build-up | N/A |
| Environmental profile | Eco-friendly natural mineral | Petroleum-derived | Petroleum-derived | Petrochemical, isocyanates | N/A |
| Suits multi-storey developments | Yes, low dead load | Yes | Yes | Yes | Compliance issues |
| Downward heat loss prevented | Up to 30% | Up to 30% | Up to 30% | Up to 30% | None |
| Best fit | Hydronic underfloor heating, multi-storey, fire-rated builds | Budget single-storey homes | Wet areas, basement floors | Tightest k-value, premium build | Not recommended under heated floors |
The honest answer. XPS polystyrene and PIR boards have a slightly better raw k-value than perlite-cement screed. But on real-world performance under hydronic underfloor heating, once you account for the reinforcing mesh, the thicker top screed, the combustibility risk and the long-term compression of foam boards under heavy floor finishes, SUNPERL® perlite is the safer, simpler and more cost-effective long-term choice. Synergy installs perlite on every hydronic project we deliver.
We coordinate closely with your builder, plumber and tiler to deliver a cured, level, load-bearing SUNPERL® perlite screed substrate ready for hydronic underfloor heating pipes, without rushing the cure and without compromising on mix ratio or slab adhesion.
Our technician visits your home or site to inspect the concrete slab, measure each room, confirm the underfloor heating brief and recommend perlite layer thickness and screed build-up. We also confirm whether the project is a new build or major renovation, that drives the install sequence and how we coordinate with your other trades.
SUNPERL® expanded perlite is mixed with 42.5N grade Portland cement in the correct ratio for a hydronic underfloor heating substrate. Bonding liquid is added to the mix to ensure proper adhesion to the concrete slab. No premix bags, no shortcuts on ratio, every batch is proportioned on site for the day's pour.
Additional bonding liquid is slushed onto the concrete slab, then the 20 mm perlite-cement screed is applied and screeded level across the floor area. Layer thickness is scaled up or down to suit pipe diameter and your final floor build-up, specified during site assessment.
The perlite screed is cured for 10 to 14 days to reach the compressive strength required to securely hold the underfloor heating pipes. Synergy never short-cuts this cure window, it's the single biggest factor in lifetime substrate stability and the strength your pipes will pull against for the next 50 years.
Once cured, hydronic underfloor heating pipes are fastened directly onto the perlite substrate using nails and saddles. We then hand off a level, load-bearing surface to your tiler or screeder for the final floor finish. From there, our Centurion, Cape Town and Polokwane branches provide ongoing support for the lifetime of the building.
Indicative installed rates for a standard 20 mm SUNPERL® perlite-cement screed layer. Actual project pricing depends on area, slab access and specification, request a free site-specific quote.
Typical petroleum-based EPS/XPS board insulation
Natural volcanic mineral insulation, installed
Ten of the most common questions we field from homeowners, architects and builders looking at energy-efficient home insulation in Gauteng, the Western Cape and Limpopo. Don't see yours? Send it through and we'll answer personally.
Perlite is a naturally occurring, non-toxic volcanic rock that expands up to 20 times its original volume when heated above 870°C. The expansion process forms millions of glass-sealed air bubbles, resulting in outstanding lightweight and insulating characteristics. Mixed with 42.5N cement and applied as a 20 mm screed beneath hydronic underfloor heating pipes, it forms a non-combustible, load-bearing thermal barrier that directs nearly all generated heat upward into the floor finish, making it the most effective floor insulation for energy-efficient home heating systems in South Africa.
Without high-performance insulation beneath the pipes, up to 30% of the heat generated by your hydronic underfloor heating system can be lost downward into the concrete subfloor or ground. This forces your heat pump or boiler to run longer and cycle harder, dramatically increasing electricity consumption and your monthly Eskom bill while delivering less warmth where you actually feel it.
Perlite floor insulation is priced per square metre of insulated floor area. A standard 20 mm SUNPERL® perlite-cement screed installed by Synergy starts from approximately R159 per m². By comparison, typical petroleum-based EPS or XPS polystyrene board insulation runs from approximately R145 per m². Although perlite is marginally higher per m², it frequently removes the need for reinforcing mesh and allows a thinner top screed, often making it more cost-effective over the life of a hydronic underfloor heating installation. A fixed written quote is provided after a free on-site assessment.
Yes. When combined with 42.5N grade cement, SUNPERL® produces a stable, durable insulating concrete that serves as a solid, load-bearing substrate for the final floor finish. It mitigates the compression risks often associated with foam boards and rigid polystyrene sheets, important for multi-storey developments and for homes with heavy floor finishes such as natural stone.
Yes. As a mineral-based volcanic glass, perlite is non-combustible and does not emit toxic fumes when exposed to fire. It is rated Class 0 under the relevant fire-safety classifications. This is a major safety advantage over petroleum-based EPS or XPS polystyrene insulation, which is combustible.
Perlite demonstrates markedly superior thermal properties. While standard plaster sand has a thermal conductivity (k-value) of around 0.4 W/m·K, loose SUNPERL® achieves values between 0.04 and 0.05 W/m·K, making it 8 to 10 times more effective at preventing downward heat loss. As a finished cement screed it sits between 0.09 and 0.14 W/m·K, still dramatically lower than standard sand-and-cement floors.
No. Perlite is an inert volcanic mineral that will not rot, decay, absorb water or attract vermin. It preserves both its structural and thermal integrity for the entire lifetime of the building, requiring no maintenance once installed.
Yes. Perlite is a natural volcanic mineral with a minimal mining and processing footprint, and it is entirely non-toxic. It is recognised as a sustainable, high-performance thermal solution and is well-suited to homeowners and developers seeking eco-friendly, energy-efficient home insulation that aligns with Green Star and SANS energy-performance expectations.
Yes. Beyond floors, perlite can be used to plaster walls and to insulate concrete roof slabs, giving homeowners an integrated, energy-efficient home insulation solution across floors, walls and ceilings for optimal year-round thermal performance.
Polystyrene is lighter and has a slightly lower k-value in isolation, but it is combustible, requires a reinforcing mesh and a thicker top screed to handle floor loads, and can compress over time under heavy finishes. Perlite-cement screed is non-combustible (Class 0), load-bearing without added reinforcement, dimensionally stable for the lifetime of the building and lower in overall installed thickness. For most South African hydronic underfloor heating projects, perlite is the safer, simpler and more cost-effective long-term choice.
SUNPERL® perlite floor insulation works hardest as part of a complete energy strategy. Pair it with hydronic underfloor heating for the warmth it's designed to keep, with carbon fibre wall heating for retrofits and rooms above the slab, and with Tesla Powerwall 3, Sigenergy SigenStor or Deye & Sunsynk hybrid solar to power it all from the sun, so your entire home energy stack is designed and maintained by one accountable team.
If you're laying floors anyway, hydronic underfloor heating is hard to beat for new builds and major renovations.
If you're retrofitting a finished home and can't lift floors for perlite + hydronic pipes, carbon fibre wall heating gives you the same radiant comfort, installed in days, not weeks.
Store the solar energy you generate in the day and use it to heat your home through the evening, even during load shedding.
An all-in-one solar, battery and energy-management system from Sigenergy, fewer components, smarter control, faster install.
Cut geyser running costs and use the same heat-pump efficiency story to keep your hot-water bills as low as your space heating.
Affordable hybrid solar packages from R82,216, same proven hardware as our premium tiers, professionally installed nationwide.
Real reviews from real Synergy customers, sourced directly from our Google Business Profile.
"I couldn't be more thrilled with my decision to go solar, and Synergy Energy Solutions made the entire process seamless and enjoyable. From the initial consultation to the final installation, their professionalism, expertise, and dedication to customer satisfaction were evident every step of the way. The installation crew was punctual, efficient, and left my property spotless."
"Thank you Jacques and Jaco from Synergy Energy Solutions. Your professionalism and excellent service resulted in a great solar installation and solution. We are very happy and would recommend you to anyone looking for a residential or commercial solution. We can vouch for both. Well done."
"What an absolute pleasure to have Synergy as my solar provider. After I have been scammed previously by a 'reputable' company, I was unsure where to turn next. Synergy was recommended and from day one they exceeded my wildest expectations. Very professional, always friendly, prompt service and the list goes on. Thank you Jean and team, you guys rock!"
"What a pleasure to deal with Synergy, it's a company with experience and after-care service. Jacques always takes my calls (and there were many) during and after the installation, always willing to assist, always monitoring our system for optimal usage. Our site was always clean, they were always on time. Jacques and team, thank you, it's much appreciated."
"Synergy Energy Solutions is an excellent company, very good workmanship as requested. The system looks neat and professional. Thank you also for the over-and-above tasks that were performed for the preparation of the installation. The system has been running for a month now, I was always immediately assisted by competent personnel. The form, fit and function of the system is awesome!"
"I have used Synergy Solutions to do solar installations on two separate occasions. In both instances I found them to be speedy, professional, friendly and extremely competent. I can highly recommend them."
Read all 73 reviews on our Google Business Profile.
Established in 2010 and headquartered in Centurion, Synergy Energy Solutions has spent 16 years designing solar PV, battery storage, heat pump water heating, hydronic underfloor heating and carbon fibre wall heating systems for residential and commercial customers across Gauteng, Western Cape, Limpopo, KwaZulu-Natal and Mpumalanga, from Stellenbosch wine estates and Highveld farms to Polokwane bushveld lodges. The team quoting your project is the team installing it: no middlemen, no franchise mark-ups.
With branches in Centurion (Gauteng), Table View (Western Cape) and Polokwane (Limpopo), Synergy installs SUNPERL® perlite floor insulation nationwide, backed by local technical support and one phone number across all three branches: 010 601 6464.
Pretoria · Johannesburg · Centurion · Sandton · Midrand · Kempton Park · Hartbeespoort · Krugersdorp · Roodepoort
30 Pretorius Avenue, Lyttelton Manor, Centurion, 0157
010 601 6464
Cape Town · Table View · Stellenbosch · Paarl · Somerset West · Constantia · Cape Winelands · Garden Route
Unit 202, 10 Blaauwberg Road, Table View, Cape Town, 7439
010 601 6464
Polokwane · Tzaneen · Mokopane · Lephalale · Bela-Bela · Thohoyandou
47 Platinum Street, Polokwane Ext 17, Polokwane, 0699
010 601 6464
Beyond our three branches. We regularly travel to KwaZulu-Natal, Mpumalanga, Eastern Cape and North West for larger perlite and underfloor heating projects, from Stellenbosch wine estates and Highveld farms to Polokwane bushveld lodges. Outside our standard regions? Enquire with your address and we'll confirm feasibility. See our SAPVIA listing for verified installer status.
Synergy Energy Solutions is accredited by South Africa's leading electrical, solar and battery industry bodies, and by the inverter manufacturers we install, your assurance of compliant, professional installation across every solar PV, battery and hydronic heating system we deliver.
Member of the Electrical Contractors' Association of South Africa, the leading industry body for registered electrical contractors, ensuring our installations meet the highest professional standards.
An industry-led quality label that guarantees a high standard of quality, safety and compliance for small-scale solar PV installations across South Africa.
Aligned with the South African Photovoltaic Industry Association, the recognised body representing the solar PV industry and setting installation, training and quality standards nationwide.
Approved Tesla Powerwall 3 supplier and Tesla Energy Certified Installer, trained and authorised by Tesla to design, install and service Powerwall 3 systems in South Africa.
Sigenergy Certified Installer for SigenStor all-in-one solar, battery and EV charging systems, factory-trained to design, install and commission Sigenergy solutions for South African homes.
Approved Sunsynk installer, qualified and authorised to design, install and commission Sunsynk hybrid inverters and Sunsynk Lithium battery systems in South African homes.
Recognised Deye installer, experienced in the design, installation and commissioning of Deye hybrid inverters and approved Deye-compatible battery systems for South African homes.
Schedule a free, no-obligation site assessment with our perlite insulation specialists. We'll inspect your slab, calculate the perlite layer thickness for your underfloor heating build-up, give you a fixed written quote, and coordinate seamlessly with your builder and tiler.
One of our perlite insulation specialists will be in touch to discuss your project and arrange your free site assessment.
Prefer to talk now? Call us on 010 601 6464