hilti firestop systems water resistance...accordance with passive fire prevention requirements, but...

Hilti Firestop Systems

Water resistance

Water resistance

Contents

1. Introduction 3

2. Terms used 4

3. Rain resistance 6

4. Mould and mildew 7

5. Water tightness 8

6. Tested systems from Hilti 9

Water resistance

page 3

1. Introduction

Water resistance is understood by Hilti to mean a construction material’s ability towithstand the effects of water and moisture not only in the completed, occupiedbuilding, but also during the construction phase.

During the construction of the shell of a building, before it is fully sealed andweatherproof, entire floors may be flooded by rainwater. Inadequately hardenedsealants may be washed out. These products therefore require a certain degree ofrain resistance.

In rooms where humidity is high there is a risk of mould or mildew forming even aftera firestop product has hardened. In the event of the formation of mould, this musthave no negative effect on the intended function of the firestop product.

Fireproofed penetrations are expected to provide a certain degree of water tightnessin order to minimize consequential water damage in the event of accidents (burst water pipe, fire extinguishing water).

A firestop system’s water resistance is therefore an important characteristic inaddition to its main function.

Hilti firestop systems are therefore not only tested and approved internationally inaccordance with passive fire prevention requirements, but also in terms of their waterresistance in accordance with the applicable standards.

This brochure, on the one hand, is intended to point out the general principles of water resistance and, on the other, to provide information, based on practicalexamples, on the applications for which Hilti firestop products are used.

Water resistance

page 4

2. Terms used

Rain resistanceJoints and penetrations require to be fireproofed even in buildings where constructionof the shell is not yet complete.In the event of water finding its way into the building immediately after firestopproducts are installed, recently applied sealants or firestop coatings may be washedout. Users thus need to know how long it takes for such firestop products to dry andharden sufficiently so as to be no longer susceptible to damage by water or rain.DIN 52461 describes a test setup which allows the rain resistance of sealants andcoatings to be determined with reproducible results.

Mould and mildewMould in a building can attack and weaken many types of building materials. Moreover, fungus releases spores which are detrimental to the health of residents orusers of the building concerned.Even in situations where it is not the origin of the fungus, the firestop system still hasto be protected effectively.The fungus resistance of the various Hilti firestop systems is tested with the relevant types of fungus in accordance with the international standard ISO 846 and US standard ASTM G21.

Water tightnessThis is understood to mean the temporary water tightness of the firestop systems.This characteristic is important with a view to minimizing the consequential damagecaused by water in the event of an accident (fire extinguishing water, burst pipes).In accordance with the US standard UL 1479, the firestop systems are subjected to apressure approx. an 1 m (comparable to 3 feet) water column for a certain time in orderto determine whether the firestop system is capable of withstanding this pressure.

Rain resistance

Mould and mildew

Water tightness

Water resistance

page 5

3. Rain resistance

Joints and penetrations need to be sealed to prevent the spread of fire even whileconstruction work on the shell of a building is still in progress. Rain may enter thebuilding during this early stage of construction. Freshly applied water-based sealantsor coatings may be washed out if rain falls on them before their surface has dried andhardened.

This possibility cannot be ruled out, especially where curtain walling is to be installedand sealed appropriately. The gap between the facade section and the floor deck isfirst filled with mineral wool and subsequently sealed with a firestop system coating.If rain falls on the floor deck above, water may drip directly onto the freshly appliedcoating and the mineral wool on the floor below.

Facade application

Test setup for CP 672 firestop joint spray

Testing for rain resistanceThe rain resistance of water-based sealants is specified in the DIN 52461 standard.The standard requires that the sealant to be tested is applied to a test specimen andthen allowed to dry for a certain period before being exposed to "rain” for 10 minutesat a pressure of 2 bar.The difference in weight of the specimen before and after exposure to the rain issubsequently determined and a visual assessment made.

ResultsThe following Hilti firestop systems have been tested in accordance with DIN 52461:Hilti firestop system Rain resistantCP 601S elastic firestop sealant ImmediatelyCP 604 self-leveling firestop sealant ImmediatelyCP 606 firestop joint filler After 1 hourCP 672 firestop joint spray After 4 hoursCP 670 / CP 673 firestop coating After 3 hours

Water resistance

page 6

4. Mould and mildew

As a consequence of the introduction of more stringent energy-saving regulations forbuildings, the envelope of buildings are today being increasingly tightly sealedagainst moisture and draughts. Moreover, modern dispersion paints and wall coverings with a high plastics content (PVC wall coverings) form a barrier whichgreatly reduces water vapor diffusion. As a result, complaints about attack by fungusat points where thermal bridging occurs, such as at windows or doors, are becomingincreasingly common.

Measures to successfully prevent the formation of mould and mildew in a buildingmust be taken right at the planning stage. This must also include the correct choiceof components and materials and these must be used and installed correctly.

The formation of fungusFungus spores can be found almost everywhere. The following conditions encouragethe growth of fungus:• Warmth and dampness (20–35°C, 60–85% relative humidity)• Permanently damp areas• A nutrient on which the fungus can grow, e.g. materials such as wall coverings,

wood, textiles, plastics and rubber.

Under normal conditions of use, fungus in buildings typically occurs in cellars,bathrooms and kitchens or at thermal bridges, e.g. around doors and windows.

The level of moisture in a building may increase as a consequence of some exceptionalincident such as water ingress due to flooding, burst pipes or after activation ofsprinkler systems.

The formation of mould and mildew in buildings

Water resistance

page 7

The effects of fungusThere are various types of fungus. Some are seriously detrimental to the health iftheir occurrence is on a large scale. Examples of these are:• A few species of the Penicillum group• Some species from the Aspergillus group

Occupants of rooms where fungus is present often suffer headaches, eye irritationsand symptoms similar to those of the common cold. Persons of a certain dispositionmay suffer allergic reactions if the spores are inhaled over a long period. In extremecases, buildings attacked by fungus may no longer be inhabitable and may evenhave to be demolished.

An additional problem is posed by the fact that fungus uses building materials as anutrient. This means that the fungus attacks the materials where it occurs. In mildcases, the material concerned may become discolored, while in extreme cases theattack can cause a change in the technical properties of the material (e.g. strength,conductivity, elasticity).

How can the growth of fungus be prevented?In a three-person household, the water vapor released by the inhabitants themselves(30 to 100 g/h per person) and through showering, washing, and cooking as well asby plants and other sources of moisture, adds up to a total of between 6 and 14 kg ofwater vapor released each day. Similar levels of moisture also occur in factory areasor in offices.

Approximately 250 m3 of air must be moved in order to transport away 10 kg of watervapor from the interior of a building. This means that the air in the rooms concernedhas to be exchanged approximately every 2 – 3 hours in order to transport away theundesired moisture.

Other helpful everyday steps to be taken include ensuring that the rooms areadequately heated (approx. 20°C). In absolute terms, warm air is capable of absorbing more water vapor than cold air. This reduces the amount of condensationat thermal bridges. Appropriate measures should also be applied to the structure ofthe building in order to avoid or reduce thermal bridging.

Protection of building materialsVarious measures can be applied to protect building materials from attack by fungus.

In principle, 2 approaches are conceivable:a) Prevent the formation of fungus on the productb) Ensure that the product is not attacked by the growth of fungus on it and that its

functionality (fire protection) is not compromised

The formation of fungus on products used in construction can be effectively prevented by the addition of fungicide. This additive, however, can be leached out ofthe product by water or moisture during the course of time. A further problem is presented by the fact that most fungicides are hazardous to the health. The applicable concentration is therefore kept as low as possible or, as an alternative, asubstance which can be integrated in the chemical matrix of the product is used.

Accordingly, the optimum solution would be a product which, due to the use ofsuitable materials, provides no nutrition for fungi and is therefore not at risk of beingattacked. Products of this kind require no protective fungicide. This is the approachfollowed by Hilti in the development of new firestop systems.

Close-up showing the Aspergillus nigerfungus

Water resistance

page 8

Tests to determine fungus resistanceIn order to verify that Hilti firestop system products are effectively protected againstattack by fungus, an independent test institute was commissioned by Hilti to conducttests following the principles of the ASTM G 21 and ISO 846 standards. Tests withthe following 2 fungi were carried out:• Aspergillus niger• Penecillum funiculosum

Both of the these fungi are aggressive types which grow extremely quickly. They mayrelease substances that are hazardous to the health and thus present a risk to theoccupants of the affected building.

In both tests, ASTM G 21 and ISO 846, the test specimens are stored for 4 weeks on a nutrient-free mineral salt solution (Agar A) which has been sprayed with theapplicable fungus spores. This means that only the product specimens may providenutrients for the fungus. The product will not be overgrown by the fungus if it provides no nutrient. In this case, the product can be said to possess fungus resistance.

For the ISO 846 test, the specimens are stored on a nutritious solution (Agar B) containing glucose, which has also been sprayed with spores. In this case, the fungus can grow even when the product specimens provide no nutrition. It is thusmuch more difficult to obtain good results in this test. The products tested in this situation are said to have a fungistatic effect. In this test, fungicide is particularlyeffective in preventing growth of fungus on the specimens. If the fungicide is leachedout of the product, a so-called barrier halo, i.e. a fungus-free zone, forms around thespecimen.

Subsequently, the material of the Hilti firestop product is also assessed for its fitnessfor use. The surface of all specimens exposed to fungus is examined under a microscope for signs of damage.

Test results and their interpretationHilti has had all relevant Hilti firestop systems tested in accordance with ISO 846 andASTM G 21, using the nutrient-free Agar A solution. In these tests, no fungus grew onany Hilti product.

This means that all of the Hilti firestop systems tested cannot be attacked or damaged by fungus and that they remain functional despite exposure to fungus.

Detailed results are available from the original test certification.

Summary1. Fungus does not originate on Hilti firestop systems.2. The Hilti firestop systems tested are adequately protected against serious damage

by fungus.3. If a building attacked by fungus is to be rehabilitated, the firestop systems must

also be checked during the course of the work and cleaned or replaced as necessary.

4. Suitable measures must be taken to combat the cause of the fungus.

Specimen with sourrounding barrier halo

Specimen not overgrown

Specimen overgrown

Water resistance

page 9

5. Water tightness

Firestop systems help to prevent the spread of fire to other sections of a building in the event of a fire breaking out. However, the resulting losses can be greater andthe damage more severe because of the water used by firefighters or water releasedby the sprinkler system. The extinguishing water can find its way through penetrations for cables and pipes in walls or floor decks, causing damage in additional rooms. There is also always the risk of a burst pipe in a building.

The purpose of this internal test is to verify that selected Hilti firestop systems providewater tightness against a 1m water column pressure for a limited period of time. Inother words, the test shows that Hilti firestop systems are capable of preventingwater ingress in adjoining rooms or sections of a building

In order to ensure water tightness, it is essential that Hilti firestop systems areinstalled correctly in accordance with the Hilti installation instructions.

Water resistance

page 10

Test setupThe test is carried out in accordance with the principles of UL 1479, W-rating (officialUS test standard).

A block of concrete is cast with a centered, square opening.The dimensions of the block are 40 cm × 40 cm × 10 cm.The dimensions of the opening are 18 cm × 18 cm.

The opening is sealed with the firestop product, Hilti CP 601S firestop sealant in thiscase, in accordance with the firestop approval regulations.

A plexiglas tube with an internal diameter of 29 cm is then fastened to the concreteblock. The seal between the concrete and the aluminium flange holding the plexiglastube is provided by Hilti CP 619 firestop sealant.

The plexiglas tube is then filled with colored water and checked daily for leakage.

The results and their interpretationThe test is considered failed if water leaks through the firestop system.

Slight traces of dampness, especially on the concrete, do not indicate failure.

This test is not suitable for the purpose of verification of the general water tightnessof Hilti firestop systems, as is required, for example, for service entries in exteriorwalls. Interpolating of the results to higher pressures or longer testing times is alsonot permissible.

CP 601S over the opening

CP 601S with the flange and Perspextube

Key:A 1 m water columnB Water (colored)C Test specimen

A

B

C

Water resistance

page 11

6. Tested systems from Hilti

Product Rain Mould Water tightnessresistance and mildew

CCP 601S 3 3 3

CP 604 3 3 3

CP 606 3 3 3

CP 611A O 3 3

CP 612 (FS-One) O 3 ¸3CP 617 – electrical outlet boxes O 3 3

CP 620 O 3 3

CP 632 O 3

CP 636 O 3 3

CP 637 O 3 3

CP 638 O 3 3

CP 643N / CP 644 O 3 OCP 645 O 3 OCP 648 O 3 OCP 657 O 3 3

CP 670 / CP 673 3 3 3

CP 672 3 3 3

CP 675 + CP 619 O 3 3

CP 680 / CP 682 O 3 O

3 = testedO = not relevant

This brochure was produced by Hilti Corporation, LI-9494Schaan, Principality of Liechtenstein.

hilti firestop systems water resistance...accordance with passive fire prevention requirements, but...

Documents