Imperpuma BP PY4

1 m x 10 m x 4 Kg/m2 sheet of polymer-additivated bitumen with polyester felt reinforcement, finished on both sides with non-stick polyethylene film. Waterproofing bituminous sheet of polymer-additivated bitumen type LA-40-FP.

Download technical data sheet

Additional information


It is composed of a polyester felt reinforcement, a thermoplastic mastic and a non-stick polyethylene film on both sides

Features and applications

  • Bottom sheet in mono-layer system improved with modified bitumen sheets.
  • Tightness sheet for buried structures.

Instructions for use

Place by adhesion using a torch

Cautions and recommendations

  • Not recommended for mono-layer systems, bilayer system only with bituminous auxiliary sheet, top sheet in two-layer system suitable for open air and top sheet in garden roof.
  • Store horizontally in its original packaging.
  • Store away from open sky and humidity.
  • Do not apply at temperatures below - 5°C


They are sold in 25 rolls per pallet. Maximum storage time: 2 years, away from open sky at temperatures above + 5ºC

Technical data

External fire behaviour  prEN 13501-5 - PND
Reaction to fire  EN 13501-1 - E
Tightness  EN 1928 (A) - Passes
Longitudinal tensile strength  EN 12311-1 N/50 mm 600±200
Transverse tensile strength  EN 12311-1 N/50 mm 400±150
Elongation at longitudinal break  EN 12311-1 % 35±15
Elongation at transverse break  EN 12311-1 % 35±15
Resistance to root penetration  prEN 13948 - PND
Static load resistance  EN 12730 Kg ≥ 15
Impact resistance  EN 12691 mm PND
Joint resistance to  shear  EN 12317-1 N/5 cm PND
Folding ability  EN 1109 ºC ≤ - 5
Water vapour transmission  EN 1931 (m2.s.Pa)/Kg PND
Creep resistance  EN 1110 ºC ≥ 70
Dimensional Restability  EN 1107-1 % PND
Granule adhesion  EN 12039 % PND
Hazardous substances  - - PND

PND: No Performance Determined; Pass: Positive; No pass: Negative

Visible defects EN 1850-1 - Without defect
Mass EN 1849-1 Kg/m2 (3.80 - 4.40)
Lenght EN 1848-1 m 10
Width EN 1848-1 m 1
Straightness EN 1848-1 - Pass
Roll surface - m2 10
Rolls by pallets - - 25



The instructions for use are given according to our tests and knowledge and do not imply any commitment by GRUPO PUMA nor free the consumer from the examination and verification of the products for their correct use. Claims must be accompanied by the original packaging to allow a proper traceability.

GRUPO PUMA is not responsible, in any case, for the application of its products or constructive solutions carried out by the application company or other parties involved in the process and / or execution of the work, limiting the responsibility of GRUPO PUMA exclusively to the damages directly attributable to the supplied products, individually or integrated in systems, due to failures in their manufacturing process.

In any case, the drafter of the work project, the technical management or the person responsible for the work, or collaterally the application company or other parties involved in the process and / or execution of the work, must ensure the suitability of the products addressing the characteristics of them, as well as the conditions, support and possible pathologies of the work in question.

The values obtained by GRUPO PUMAS's products or its constructive solutions that, as the case may be, are determined by the EN standards or any other regulation that applies to it in each case refers exclusively to the conditions specifically stipulated in said regulation and that are referred to, among others, to certain characteristics of the support, humidity and temperature conditions, etc. without being them required in the tests obtained under different conditions, all in accordance with the relevant regulation.