Description
Unlike a grey-cement base that forces two coats of tinted primer under pale finishes, Atlas Hoter U White is the white-cement fibre-reinforced 2-in-1 EPS and XPS adhesive and basecoat that cures to a bright surface — so a light silicone or acrylic render goes on over a single primer pass, with ≥0.25 MPa adhesion and a 4-hour pot life from one 25 kg bag.
Where Atlas Hoter U White Performs Best — Light-Finish EWI Build-Ups
Atlas Hoter U White is a cement-based 2-in-1 mortar engineered for the same EPS, graphite EPS, and XPS bonding and mesh-reinforcement duty as the Grey version, but built on a premium white-cement binder with increased polymer dispersion that lifts adhesion to mineral substrates and board alike. Sold within the EPS adhesives and basecoats range at Renders World, its bright cured surface lets a light-render elevation — pale silicone, off-white acrylic, or any cool-toned thin coat — take one regular primer pass in place of the two opaque tinted coats a grey base demands.
Its natural home is facades where the finish colour is decided upstream of the basecoat order: new-build pale renders, conservation-zone whites and creams, and refurbishments with a light scheme already locked in. On graphite EPS specifically, the white basecoat also cuts the visual contrast between adhesive and board if a coat is damaged in service, so maintenance touch-ups stay less visible against the finished wall — the difference shows the day a pale topcoat sits true instead of drifting toward khaki over grey. The full colour-driven adhesive decision sits in the EPS adhesive selection guide.
Why Trade Specifiers Choose Atlas Hoter U White
- One primer pass under pale finishes: The white-cement basecoat lets a standard quartz primer cover in a single coat, saving the second tinted-primer pass a grey base requires under light renders — a measurable programme and material gain on every elevation.
- Brighter, truer topcoat colour: Pale silicone and acrylic renders sit on a white substrate without the cool grey cast that pulls warm tones toward khaki, which matters on heritage creams, conservation whites, and Scandinavian-influenced palettes.
- Increased polymer dispersion for higher adhesion: The white binder's raised polymer content lifts bond strength to mineral substrates and EPS beyond the grey base, useful on smoother or denser walls where extra grip earns its place.
- 3D microfibre crack control: Structural microfibres distribute thermal and mechanical stress across the cured layer, holding the basecoat together against hairline cracking through the elevation's service life.
- 4-hour pot life at 20 °C: Mixed mortar stays workable for around four hours — identical to the Grey variant — so a two-person team batch-mixes at the station and applies long basecoat stretches without restarting the mixer every 90 minutes.
- ≥0.25 MPa to concrete, ≥0.08 MPa to EPS: Tested bond strength on mineral substrates and board surfaces supports certified Atlas ETICS detailing where Building Control and warranty providers verify the specification.
- Lower quartz primer consumption: The smooth fibre-reinforced finish pulls primer evenly without thirsty patches, reducing primer use on the next stage on long runs.
Technical Specifications — Atlas Hoter U White Data Sheet Highlights
| Property | Value |
|---|---|
| Product type | White-cement 2-in-1 adhesive and reinforcing mortar |
| Composition | White cement, mineral fillers, increased polymer dispersion, microfibres |
| Pack size | 25 kg bag |
| Colour | White (premium white-cement binder) |
| Mixing ratio | 5.0–5.5 l clean water per 25 kg |
| Pot life | ~4 hours at 20 °C |
| Open time | Min. 25 minutes |
| Application temperature | +5 °C to +25 °C (substrate and ambient) |
| Consumption — board fixing | 4.0–5.0 kg/m² (≈5 m² per bag) |
| Consumption — basecoat and mesh | 3.0–3.5 kg/m² (≈7 m² per bag) |
| Reinforced layer thickness | 2–5 mm |
| Adhesion to concrete | ≥0.25 MPa |
| Adhesion to EPS | ≥0.08 MPa |
| Standards / certification | EN 15824:2017 · ETA within Atlas ETICS |
| Application method | Hand trowel or rendering machine |
| Shelf life | 12 months (sealed, dry storage) |
| Manufacturer | Atlas Sp. z o.o. |
How to Apply Atlas Hoter U White — Mixing, Mesh Embedding, and the Single-Primer Workflow
Mix the 25 kg bag into 5.0–5.5 litres of cool, clean water — powder into water — with a paddle mixer on low speed until lump-free, rest five minutes, then remix briefly to activate the polymers. Apply between +5 °C and +25 °C. For board fixing, lay a 3–4 cm perimeter band with three to six central dots, then press each board until contact covers at least 40 % of the rear face, the figure the certified Atlas ETICS detail requires. On dense concrete the mortar bonds directly; on absorbent or dusting substrates a pass of Atlas Uni-Grunt evens out suction first.
After the bonding layer cures at roughly 24 hours and fixings are in, trowel a 2–3 mm continuous basecoat, embed Atlas 150 g/m² fibreglass mesh with minimum 100 mm overlaps, and smooth a second thin pass so the mesh sits in the outer third of the layer. Once cured, the white surface accepts a single light pass of quartz primer rather than the two tinted coats a grey base needs under pale renders — the workflow gain that pays back the white variant on light-finish elevations. The basecoat and mesh reinforcement guide covers overlap discipline and corner detailing in full.
Installation Notes — Conditions, Drying Times, and Finishing
Hold both substrate and ambient temperature between +5 °C and +25 °C for at least 24 hours after application. Mechanical fixings are mandatory on certified ETICS regardless of adhesive colour — install them through the boards after the bonding layer has fully cured, typically at 6–8 per m² for the wind-load zone, then encapsulate the anchor heads within the white reinforced basecoat. Confirm board-face temperature with an infrared thermometer, since dark graphite EPS warms faster than masonry and can flash-dry the thin layer before the mesh beds in.
Allow the finished basecoat a minimum of three days to cure before priming and the pale decorative render, extending that in cool or humid weather so the white surface is fully ready for the lighter primer regime. On a full Atlas build-up, Hoter U White (board fixing) → mechanical fixings → Hoter U White (mesh basecoat) → single-pass quartz primer → a pale Atlas thin-coat silicone render completes the facade inside one warranted system. Protect the bright surface from boot tracks and scaffold scuffs, and clean tools with water before the mortar sets.
Pro Tips From UK Installers Using Atlas Hoter U White
Experienced installers rely on a few habits specific to a white basecoat under light renders — the reward is a bright, mark-free surface and no over-ordered primer.
- Protect the white surface from boot tracks: The bright basecoat shows soles, scaffold scuffs, and tool drag more than grey, so drop dust sheets at the base of each elevation before the basecoat day starts, not after the first mark.
- Order primer to the single-coat rate: Calculate quartz primer against the one-pass rate the white basecoat enables, not the double-coat rate quoted for grey jobs — over-ordering primer is the most common material waste on light-render projects.
- Watch the wet edge, not the clock: The 25-minute open time governs mesh embedding, and a lost wet edge telegraphs through the finish — which on white renders shows under raking light far sooner than on dark coats.
- Use the long pot life for batch runs: The four-hour window suits station mixing on light-render jobs of 200 m² and above, with one operative trowelling while another preps the next bay.
- Reserve white for genuinely light schemes: Under mid and dark topcoats the white-cement advantage delivers no workflow gain, so keep it for pale finishes where the single-primer saving is real.
How Atlas Hoter U White Compares to the Grey Variant and Sibling Adhesives
Hoter U comes in white and grey cement on the same fibre-reinforced base, and Renders World stocks a universal wool-and-EPS alternative for mixed-board buildings. The table sets the three against each other so the choice follows the topcoat colour and board type on your elevation.
| Variant | Key Spec | When to Choose |
|---|---|---|
| Atlas Hoter U White 25 kg | White cement · increased polymer · single-primer | Light and pastel topcoats, brighter finish |
| Atlas Hoter U Grey 25 kg | Grey cement · same fibre base · lower cost | Mid and dark topcoats, best economy |
| Roker U Grey 25 kg | Universal · mineral wool + EPS rated | Mixed wool/EPS buildings, one adhesive |
Is Atlas Hoter U White Right for Your Project?
- Yes — when the decorative coat is white, off-white, pastel, or any light shade: The bright white-cement basecoat saves the second tinted-primer pass a grey base forces on the next stage, and the raised polymer content lifts adhesion on smoother substrates.
- Mid or dark-tone finish coat instead? The grey-cement GRP sibling Atlas Hoter U Grey 25 kg delivers identical 4-hour pot life and ETA-certified bond strength at a lower price point — the better economic choice when grey show-through is invisible under the finish.
- Insulating with mineral wool? Mineral wool needs a more vapour-permeable adhesive engineered for the slab structure — Roker U Grey 25 kg is the wool-and-EPS-rated alternative in the same range, keeping the A1 fire layer inside its certification envelope.
- For a full white-finish specification, pair it with the EPS insulation boards range as the thermal layer, then a single-pass quartz primer and a pale silicone render — staying inside one certified ecosystem protects warranty cover on the finished facade.
FAQ — Atlas Hoter U White Coverage, Compatibility, and Ordering
How many bags of Atlas Hoter U White do I need per 100 m² of EWI?
At average rates of 4.5 kg/m² for board fixing and 3.5 kg/m² for the basecoat, a 100 m² elevation consumes around 450 kg + 350 kg = 800 kg, which is 32 bags. Order 35 bags per 100 m² to absorb the 10 % wastage from uneven substrates, complex window detailing, and offcut losses on long basecoat runs. As a 2-in-1 product it covers both stages, so there is no separate adhesive and basecoat order to reconcile.
When is the white version worth the upgrade over Hoter U Grey?
Choose white whenever the decorative finish is light enough that grey show-through would force a tinted primer regime — pale silicone, off-white acrylic, conservation creams, and pastel schemes all benefit from the single-primer-pass saving. On mid-tone and dark-tone finishes the grey sibling is the cost-effective spec, since the white-cement advantage delivers no workflow gain under a deep colour. The choice comes down to finish-coat colour, not bond performance.
Can I skip the primer entirely under a pale render on the white basecoat?
The white surface removes the colour-masking role of the primer, but a standard manufacturer-approved quartz primer is still recommended to equalise substrate suction before the silicone or acrylic topcoat. The workflow gain is moving from two tinted-primer coats to one regular pass, not from one coat to none — the primer's mechanical-key and suction-regulating role remains essential to the certified build-up.
Do I still need mechanical fixings if the adhesive is this strong?
Yes — certified ETICS installations rely on mechanical anchors to manage wind-load pressures and long-term structural movement, regardless of adhesive grade or colour. Install the fixings through the boards after the bonding layer has fully cured, typically at least 24 hours, then apply the reinforced basecoat over the anchor heads so they are fully encapsulated within the white layer. The adhesive bond and fixings together form the dual-retention system the certification requires.
How long does the mixed mortar stay workable?
At 20 °C the mixed paste stays workable for approximately four hours, identical to the grey variant. Plan batch sizes around that window — a two-person team can comfortably mix 50 kg at a time on warm summer days and still finish the bucket before it stiffens, keeping pace with the larger primer-saving runs that white-basecoat projects favour. Above +25 °C the window shortens, so shade the bucket and mix to demand.
How long can I store unopened bags on site?
Sealed bags keep for 12 months from the manufacture date when stored off the ground in dry conditions, ideally on a pallet under a weather sheet rather than on bare concrete. Once a bag is opened, transfer unused powder into a sealed plastic tub the same day, since humid UK air reduces the pot life and bond strength of partially used bags within a week.
Technical Documentation — Atlas Hoter U White TDS and DoP