Thatch Fireboard System

System Overview:

The Thatch Fireboard System is designed to meet the criteria as recommended by Building Control for both spread of flame and penetration. The combination of TAS100 Fireboards for Integrity and Thatchbatts® for Insulation makes this system an ideal fire protection solution, with the added benefit of providing thermal insulation values.

The Thatch Fireboard System will offer a fire barrier in accordance with BS476 Part 3: 2004 & CEN/TS 1187:2012. Thatchbatts® are designed to be friction fitted between roof timbers that are set at 400mm centres. Thatchbatts® are non-combustible, semi-rigid, high-quality resin bonded mineral rock slabs. These are ideally suited for use within the construction of a thatched roof because they offer zero spread of flame and good thermal transfer properties. 

The Complete Roof System:

Thatch Coat Work & Ridge

Breather Membrane

TAS100 Thatch Fireboard

Intumescent Joint Sealer

Minimum 50mm Thatchbatt® Slab

Vapour Control Layer

Finishing layer (plaster, gypsum skim, lath & plaster etc) 

TAS100 Thatch Fireboard

TAS100 Thatch Fireboard is an environmentally friendly calcium silicate board offering a fire barrier in accordance with BS476 Part 3: 2004. When used in conjunction with Thatchbatts® the TAS100 offers a comprehensive fire barrier.

Benefits

Zero Spread of flame

Easy to install

Water Resistant

Impact Resistant

Water Vapour Permeable

Termite, mould and insect proof

Can be cut, drilled, nailed & screwed with no splitting 

Specification

Dimensions: 2400x1200x9mm

Weight: 30kg per board

Normal Dry Density (Average): 975 + 12.5% kg/m³

Thermal Conductivity 0.22W/mk

Tensile Strength: 4.5Mpa

Thermal Conductivity, λR: 0.22 W/mK

Thermal Expansion: 9 x 10–6 m/mK (0 to40°C)

Water vapour resistivity: 80MNs/gm

Testing

BS476: Part 3: 2004 - Classification and method of test for external fire exposure to roofs

CEN/TS 1187:2012, test 4 - Test method for external fire exposure to roofs

EN 13501-5:2005 – Classification report for external fire exposure to roofs

Euroclass A1 to BS EN 13501-1

Class 0 to UK Building Regulations

Intumescent Joint Sealant

One tube of sealant will cover approximately 3 x TAS100 Thatch Fireboards. The shelf life of the sealant in unopened packaging in a cool and dry storage place at temperatures between +5°C to +25°C is twelve months.

Intumescent Joint Sealant is used in conjunction with TAS100 Thatch Fireboards and is required as part of the Dorset Model. All joints must be sealed with a bead of Intumescent Joint Sealant.

Thatchbatts®

Thatchbatts® are non-combustible, semi-rigid, high-quality resin bonded mineral rock wool slabs. The Thatchbatts® are manufactured to a width of 400mm to allow them to be installed between the roof joists. They have a high density for increased fire protection on the underside of thatched roofs. Thatchbatts® will also improve thermal and acoustic values. When Thatchbatts® are used in conjunction with other components in the roof system; they can help to achieve U-Values in the region of 0.16 to 0.18 depending upon the thickness selected.

Benefits

Zero spread of flame

Easy to cut and install

Water repellent

Thermal & acoustic insulation

Lightweight

Reduces Heat Transfer

Improves insulation U-Values 

Specification

Dimensions:

Length 1200mm

Width 400mm

Depth 50mm  

Weight: 3.5kg/m²

High Density

The Thatchbatts® are designed to be friction fitted between roof timbers that are set at 400mm centres. Thatchbatts® are non-combustible, semi-rigid, high quality resin bonded mineral rock slabs. These are ideal for use within the construction of a thatched roof because they offer zero spread of flame and good thermal transfer properties.

Vapour Control Layer (VCL)

Modern living under thatch has changed in the last 10 to 15 years, with the introduction of modern central heating, double or secondary glazing, power showers and vaulted ceilings. All of these areas have an effect on the amount of vapour that is generated and how this is controlled. In addition to this the likes of Building Control and the insurance companies are keen to have fire barriers fitted to the underside of the thatch and again these can change the way that the building performs.  

It is widely accepted in the construction industry that in addition to sufficient levels of insulation, vapour control layers are required to control vapour and reduce the risk of condensation.

Many thatched buildings with a fire barrier system installed are either new build or fire damaged. Either way the main fabric of the building will have been subjected to water. As part of the drying process, large amounts of water vapour will be created. Subject to the design of the roof, consideration needs to be given to installing a vapour check before the insulation, fireboards and thatch, this is with a view to reducing the risk of these materials becoming saturated and therefore prolonging the drying out process.

Many products are available ranging from foil backed plasterboards to high performance membranes, but it is important to install the correct system that best suits each individual building. Manufacturers are usually able to discuss the exact requirements of the building and recommend the most suitable product.

Finishing Layer (plaster, gypsum skim, lath & plaster etc.)

A range of products are available and this will be down to the owner, architect, building control, conservation or listed buildings officer etc to agree between themselves.

General Notes

All materials used must comply with relevant Building Regulations and Standards. All components of this system should be installed in a professional like manner and in strict accordance with our instructions. The materials should be kept in a dry and frost free environment before and during installation. Prior to thatching works taking place the materials should be protected from the elements at all times.   

The components within the Thatch Fireboard System contribute to a part of the overall roof construction. Consult with an architect regarding the performance of the complete roof structure and requirements for ventilation, breather membranes, VCLs etc. 

Additional information for both TAS100 Thatch Fireboard and Thatchbatts® is available on our website www.thatchingadvisoryservice.co.uk or by contacting us on 01297 23671