30W Water-Blown Spray Foam | Rayston Rigid SPF Insulation
Contents
- What is 30W spray foam and when should you specify it?
- Water blowing agent and two-component system make-up
- Applied foam properties: density, closed cells, λ, μ, water absorption and fire
- Aged thermal performance table (thickness / λ / R)
- Mix ratios and site application conditions
- Component properties and laboratory reactivity
- Safety, storage, equipment cleaning and empty containers
- 30W vs other Rayston grades: which one to choose?
- 30W spray foam: FAQ
- Engineering summary
- Related links
Rayston Spray Foam 30W by Krypton Chemical: a water-blown rigid spray polyurethane foam with 28–35 kg/m³ applied density and λ = 0.031 W/m·K, free of HFCs and HCFCs, for spray-applied thermal insulation — figures from the technical datasheet.
- Product: Rayston Spray Foam 30W
- Grade: 30W · water-blown
- Application: spray-applied thermal insulation
30W spray foam (Rayston Spray Foam 30W) is a two-component rigid spray polyurethane foam system from Krypton Chemical, S.L., designed for spray-applied thermal insulation of vertical walls and interior ceilings where the surface is not subject to permanent loads. The blowing agent is water (water-blown), with no HFCs, HCFCs or VOCs according to the datasheet. Applied density is 28–35 kg/m³, declared thermal conductivity is λ = 0.031 W/m·K, closed-cell content is < 80% and the water vapour diffusion resistance factor is μ ≥ 60, according to the official technical datasheet (last revised 02/06/2026).
This article covers one grade of the Rayston Spray Foam range (the water-blown W line). To compare all grades, see the general guide: spray polyurethane foam. For the open-cell grade, see 8W spray foam; for the closed-cell HFO grade, see HFO 40 spray foam.
01
What is 30W spray foam and when should you specify it?
30W spray foam (Rayston Spray Foam 30W) is a rigid polyurethane foam made from a two-component system (polyol + isocyanate). It is sprayed directly onto the substrate to form a continuous, fully adhered insulation layer that limits thermal bridging at corners and joints.
Use declared in the datasheet:
- Spray-applied thermal insulation on surfaces not subject to permanent loads, such as vertical walls and ceilings from the inside.
- On façades: repels water while still allowing the construction to breathe to some degree.
According to the official technical datasheets, the product contains no fibres and no biohazardous materials. It is intended for industrial and professional use only and is not suitable for DIY. Per the datasheet, the cured foam is 100% recyclable by environmentally friendly mechanical means and requires no gas capture for recycling or disposal.
Manufacturer: kryptonchemical.com.
Internal links: Knowledge base · Products · Documents.
02
Water blowing agent and two-component system make-up
30W spray foam uses water as its blowing agent. This places it in the water-blown family of the Rayston line (30W / 40W / 50W), as opposed to the HFO grades (HFO 35 / HFO 40 / HFO 50) and the 8W open-cell grade.
According to the datasheet, the system is free of ozone-depleting substances and fluorinated greenhouse gases: it contains no HFCs, HCFCs, VOCs or similar. The declared text states that thermal conductivity λ remains stable from installation throughout the life of the product.
Designation code according to the datasheet:
PU EN 14315-1-CCC2-CT4 (20)-GT18(20)-TFT10(20)-FRB30(20)-W0,2-MU60
The reference standard for use as thermal insulation in buildings (ThIB) is EN 14315-1:2013, together with guidance document NB-CPR/SG19-17/167r2 dated 24/01/18. The product name on the CE marking block of the 30W sheet is Rayston Spray Foam 30W (matching the document title).
03
Applied foam properties: density, closed cells, λ, μ, water absorption and fire
Applied density
28–35 kg/m³
UNE EN 1602
Closed-cell content
< 80%
— (row notes “does not allow water through”)
Reaction to fire
Class E (all thicknesses)
UNE-EN 13823:2002
| Property | Value | Standard / TDS reference |
|---|---|---|
| Applied density | 28–35 kg/m³ | UNE EN 1602 |
| Free-rise density (lab) | 26–30 g/L | EN 14315-1:2013 |
| Closed-cell content | < 80% | — (row notes “does not allow water through”) |
| Declared thermal conductivity λ | 0.031 W/m·K | UNE-EN 12.667 |
| Reaction to fire | Class E (all thicknesses) | UNE-EN 13823:2002 |
| Short-term water absorption | ≤ 0.2 kg/m² | EN 14315-1:2013 |
| Water vapour diffusion resistance factor μ | ≥ 60 | EN 14315-1:2013 |
Brief engineering notes:
- An applied density of 28–35 kg/m³ makes this the lightest grade of the rigid W line, ahead of 40W (38–42) and 50W (48–56).
- Closed-cell content is declared as < 80% in the datasheet, and the designation code carries CCC2.
- No numerical compressive strength is given for 30W in the datasheet.
- Reaction to fire is declared as Class E for all thicknesses, and the CE marking block states that reaction-to-fire performance does not deteriorate over time.
04
Aged thermal performance table (thickness / λ / R)
Base the project’s thermal calculation on the target-thickness row of the datasheet’s aged performance table, not on the general declared value alone. For 30W spray foam, λ = 0.031 stays the same for all thicknesses from 30 to 200 mm, and thermal resistance R rises in direct proportion to thickness.
R (m²·K/W)
Aged λ (W/m·K) 0.031 · thickness 30–200 mm
30 mm
1.00
35 mm
1.15
40 mm
1.30
45 mm
1.45
50 mm
1.60
55 mm
1.70
60 mm
1.95
65 mm
2.10
70 mm
2.25
75 mm
2.40
80 mm
2.60
85 mm
2.75
90 mm
2.90
95 mm
3.05
100 mm
3.25
105 mm
3.40
110 mm
3.55
115 mm
3.70
120 mm
3.85
125 mm
4.05
130 mm
4.20
135 mm
4.35
140 mm
4.50
145 mm
4.70
150 mm
4.85
155 mm
5.00
160 mm
5.15
165 mm
5.30
170 mm
5.50
175 mm
5.65
180 mm
5.80
185 mm
5.95
190 mm
6.15
195 mm
6.30
200 mm
6.45
Worked example: at 50 mm the grade achieves R = 1.60 m²·K/W. At 100 mm this becomes R = 3.25, and at 200 mm it reaches R = 6.45 — with λ = 0.031 in every declared row.
| Thickness (mm) | Aged λ (W/m·K) | R (m²·K/W) |
|---|---|---|
| 30 | 0.031 | 1.00 |
| 35 | 0.031 | 1.15 |
| 40 | 0.031 | 1.30 |
| 45 | 0.031 | 1.45 |
| 50 | 0.031 | 1.60 |
| 55 | 0.031 | 1.70 |
| 60 | 0.031 | 1.95 |
| 65 | 0.031 | 2.10 |
| 70 | 0.031 | 2.25 |
| 75 | 0.031 | 2.40 |
| 80 | 0.031 | 2.60 |
| 85 | 0.031 | 2.75 |
| 90 | 0.031 | 2.90 |
| 95 | 0.031 | 3.05 |
| 100 | 0.031 | 3.25 |
| 105 | 0.031 | 3.40 |
| 110 | 0.031 | 3.55 |
| 115 | 0.031 | 3.70 |
| 120 | 0.031 | 3.85 |
| 125 | 0.031 | 4.05 |
| 130 | 0.031 | 4.20 |
| 135 | 0.031 | 4.35 |
| 140 | 0.031 | 4.50 |
| 145 | 0.031 | 4.70 |
| 150 | 0.031 | 4.85 |
| 155 | 0.031 | 5.00 |
| 160 | 0.031 | 5.15 |
| 165 | 0.031 | 5.30 |
| 170 | 0.031 | 5.50 |
| 175 | 0.031 | 5.65 |
| 180 | 0.031 | 5.80 |
| 185 | 0.031 | 5.95 |
| 190 | 0.031 | 6.15 |
| 195 | 0.031 | 6.30 |
| 200 | 0.031 | 6.45 |
05
Mix ratios and site application conditions
Mix ratio by volume (polyol : isocyanate)
100:100
Mix ratio by weight
100:108
Component temperature
30–60 °C
Working pressure
60–120 bar
Ambient temperature
0 to 40 °C
Relative air humidity
< 90%
Wind speed
< 30 km/h
Substrate temperature
5–40 °C
Substrate moisture
No surface condensation
| Condition | Value in the 30W datasheet |
|---|---|
| Mix ratio by volume (polyol : isocyanate) | 100:100 |
| Mix ratio by weight | 100:108 |
| Component temperature | 30–60 °C |
| Working pressure | 60–120 bar |
| Ambient temperature | 0 to 40 °C |
| Relative air humidity | < 90% |
| Wind speed | < 30 km/h |
| Substrate temperature | 5–40 °C |
| Substrate moisture | No surface condensation |
Apply with dedicated spray equipment at the mix ratios above. The manufacturer’s recommendations do not relieve the applicator of reviewing the application method and running preliminary trials whenever there is doubt about the system’s suitability for site conditions.
06
Component properties and laboratory reactivity
The following values are given at 20 °C in the datasheet section on supplementary component information and reactivity:
Hydroxyl value
Polyol: 180–220 mg KOH
DIN-53240-2
Viscosity
Polyol: 250–400 mPa·s
Isocyanate: 180–250 mPa·s
INT-IT-17
NCO content
Isocyanate: 30–32%
UNE-92120-1
| Property | Polyol | Isocyanate | Standard |
|---|---|---|---|
| Hydroxyl value | 180–220 mg KOH | — | DIN-53240-2 |
| Viscosity | 250–400 mPa·s | 180–250 mPa·s | INT-IT-17 |
| NCO content | — | 30–32% | UNE-92120-1 |
| Cream time | 4 ± 1 s | EN 14315-1:2013 | |
| Thread (string) time | 10 ± 1 s | EN 14315-1:2013 | |
| Drying (tack-free) time | 8 ± 1 s | EN 14315-1:2013 | |
| Free-rise density | 26–30 g/L | EN 14315-1:2013 |
These are reference laboratory times; working times on site depend on component temperature, pressure and ambient conditions within the ranges above. The polyol water content is not stated in the 30W sheet.
07
Safety, storage, equipment cleaning and empty containers
Occupational safety
Component B of 30W spray foam contains isocyanates. Always follow the safety data sheet (MSDS): good ventilation and/or respiratory protection (organic vapour + particulate filters) together with protective clothing. Use the product only for the applications described in the datasheet; it is for industrial and professional use and not suitable for DIY.
Storage
Store both components between 10 and 25 °C, protected from moisture ingress. Under suitable storage conditions and in the original packaging, the maximum shelf life is 6 months from the date of manufacture.
Equipment cleaning
After application, clean the machine carefully to avoid contaminating the next system. Solvents are discouraged for cleaning machine parts; a plasticiser-based cleaning fluid such as Rayston Fluid is preferred. Remove component B completely from any parts exposed to air and replace it with cleaning fluid.
Empty containers and environment
Handle empty containers with the same precautions as full ones and hand them over as hazardous waste to a licensed waste manager. A and B can be mixed 1/1 to obtain an inert material, provided the quantity does not exceed 5 litres, to avoid a dangerous build-up of heat. Do not mix residues with any other product without knowing the possible reactions.
08
30W spray foam vs other Rayston grades: which one to choose?
Choosing a grade is a design decision driven by the application, density, λ, μ and any declared compressive requirements — not by the trade name alone. Within what the 30W datasheet figures support:
1
Water-blown, 28–35 kg/m³ applied density, declared λ 0.031, μ ≥ 60 within the rigid W line → 30W is the direct candidate.
2
Higher density within the same water-blown family → compare 40W spray foam (38–42 kg/m³, μ ≥ 70) or 50W spray foam (48–56 kg/m³ with a declared compressive strength) in their detailed articles.
3
Closed cells > 90%, declared λ 0.028 and μ ≥ 80 within the HFO range → see HFO 40 spray foam, or HFO 35 spray foam and HFO 50 spray foam.
4
Declared sound insulation + lightweight open cells → 8W, not 30W.
This section does not replace a thermal calculation for the building, nor the technical datasheet of the selected grade. For the full side-by-side comparison of all grades, see the spray polyurethane foam guide.
09
30W spray foam: FAQ
What is 30W spray foam, in short?
A two-component rigid polyurethane foam system (Rayston Spray Foam 30W) from Krypton Chemical, water-blown, with an applied density of 28–35 kg/m³, for spray-applied thermal insulation on surfaces not subject to permanent loads.
What is the declared thermal conductivity?
λ = 0.031 W/m·K to UNE-EN 12.667. In the ageing table, λ stays at 0.031 for every thickness from 30 to 200 mm; use the target-thickness row for R.
Is 30W spray foam closed-cell?
Closed-cell content is declared as < 80% in the datasheet (the row notes “does not allow water through”), and the designation code carries CCC2. This differs from the > 90% closed-cell content declared for the HFO grades.
What is the correct mix ratio?
100:100 by volume and 100:108 by weight (polyol : isocyanate).
Is it suitable for permanent loads?
No, according to the datasheet wording: application on surfaces not subject to permanent loads (typically vertical walls and interior ceilings). Any use outside this scope requires an independent engineering decision.
What is the reaction-to-fire classification?
Class E for all thicknesses, according to UNE-EN 13823:2002.
Can it be applied as a DIY job?
No. The product is for industrial/professional use only and is not suitable for DIY.
Where can I compare 30W with HFO 40, 40W and 8W?
In the spray polyurethane foam guide, and in the HFO 40 spray foam article for the closed-cell HFO grades.
10
Engineering summary
30W spray foam (Rayston Spray Foam 30W) is a rigid, water-blown grade in Krypton Chemical’s W line: applied density 28–35 kg/m³, declared closed cells < 80%, declared λ of 0.031 with a constant λ in the ageing table from 30 to 200 mm, μ ≥ 60, short-term water absorption ≤ 0.2 kg/m² and reaction to fire Class E. Its declared use is spray-applied thermal insulation on surfaces not subject to permanent loads. Confirm the final choice against the datasheet figures and the project thickness, and refer to the general guide and HFO 40 when comparing with the other grades.
11
Related links
General guide and published grades
Grade articles
30W
Rayston Spray Foam 30W
| Grade | Trade name | Article |
|---|---|---|
| 8W | Rayston Spray Foam 8W | 8W spray foam |
| 30W | Rayston Spray Foam 30W | This article |
| 40W | Rayston Spray Foam 40W | 40W spray foam |
| 50W | Rayston Spray Foam 50W | 50W spray foam |
| HFO 35 | Rayston Spray Foam HFO 35 | HFO 35 spray foam |
| HFO 40 | Rayston Spray Foam HFO 40 | HFO 40 spray foam |
| HFO 50 | Rayston Spray Foam HFO 50 | HFO 50 spray foam |
Distributors
Get in touch about the supply and application of 30W spray foam (Rayston Spray Foam 30W).
Knowledge
Contact
For technical enquiries, please use the Distributors button above.