A load bearing thermal insulation block which eliminates the cold bridge at the wall/floor junction.

Marmox Thermoblock is a highly insulating, load-bearing building block that replaces the bottom course of blocks or bricks in a wall to eliminate or significantly reduce the thermal bridge at the wall floor junction. Our thermal bridging block is made of a strong and rigid epoxy-concrete frame that is integrated with our own fire-resistant XPS that gives the outstanding thermal insulation providing y values of between 0.03 to 0.07W/mK.

Although Thermoblocks are lightweight they are extremely strong and stable having a mean compressive strength of 9.0N/mm2 so can be used in most walls. Additionally, because they are impermeable to water they can be used in damp conditions without any deterioration in their insulating properties. So, not only do Thermoblock thermal insulation products reduce thermal bridging, but they also create a moisture barrier.

Marmox Thermoblock can be associated with the NBS clause: “F30 – accessories/ sundry items for brick/ block/ stone walling”

Guaranteed Compliance to Building Regulations

All building regulations in the UK and Ireland now say: “The building fabric should be continuous over the whole building envelope and constructed so that there are no reasonably avoidable thermal bridges in the insulation layers caused by gaps in the various elements.”

Marmox Thermoblock satisfies this requirement perfectly by connecting the wall insulation with the floor insulation.

The BBA certified Thermoblock was created to provide an easy, affordable and effective solution for the problem of thermal bridging. One junction of major concern has been where the wall (masonry OR timber frame) meets the floor but using Marmox Thermoblock will guarantee compliance with current regulations and also with proposed zero carbon regulations.

Guaranteed Compliance to the Code for Sustainable Homes

Although the Code for Sustainable Homes has now been withdrawn, code compliant properties are still being built. It can be demonstrated that incorporating Thermoblock into the design will reduce associated CO2 emissions significantly to allow the property to be categorized as at least Class 4 (similar to current Part L / Section 6) and with other measures will contribute to achieving CfSH levels 5 and 6. (similar to proposed 2016 zero carbon Part L)

Target Fabric Energy Efficiency Standards (England) and Target Primary Energy Consumption (Wales)

These two additional requirements (FEES and TPEC) that are now part of the both the English and Welsh building regulations use the fabric first approach. Whereas previously designers could offset associated CO2 emissions by incorporating renewable technologies to compensate for lower performing insulation, these standards now demand specific performance levels of the fabric insulation to be achieved. Marmox Thermoblock forms part of the fabric insulation and therefore is the obvious solution to achieving these standards.

How to Design a Thermally Efficient Wall-Floor Junction

Marmox Thermoblock is not an insulating building block like an aircrete block. Typically it replaces just the bottom row of blocks at floor level and in conjunction is used with aircrete blocks in the rest of the wall to stop the cold bridge at the critical wall/floor junction.

The standard block thickness in the UK as a 65mm high block, this is because this is the typical UK brick height and this thickness has been designed to give the necessary insulation required. To achieve an R Value of 2, we can also manufacture a 100mm thick version.

The block is available in three widths: 100mm, 140mm and 215mm and are suitable to form the base of walls comprising brick, block or wooden frame.

In the UK, typically it is used at the base of the inner leaf of a wall but elsewhere in Europe where the product has been popular for many years it is commonly used at the bottom of solid walls, external leaves, wall/roof junctions, below roof eaves and at thresholds beneath window and door frames; essentially anywhere where a strip of structural insulation is required.

BRE Third Party Accredited Junction Details – Thermal Models

The performance of Marmox Thermoblock in several common wall/floor junction details has been independently assessed and certified by the BRE. The BRE scheme offers an on-line database of independently assessed and certified thermal junction details which can be used in the SAP/SBEM energy assessment of the building to ensure it meets the appropriate UK and Irish building standard requirements. Using these results will save architects and designers both time and money because they will not need to have their designed modelled themselves.

Junctions incorporating the 100mm and 140mm wide block have been thermally modelled to provide a series of psi values and temperature factors (surface condensation factor fRSI) for two wall types:

With cavity walls: a)slab on ground, b) beam and block, c) suspended timber frame.

With timber frame construction: a) slab on ground, b) suspended timber frame.

Architects and Energy Assessors simply log onto BRE’s site and click the junction type required. BRE-Global is a UKAS accredited laboratory which gives confidence and assurance to designers that using Thermoblock in the common positions that have been modelled can guarantee compliance to the appropriate building standards. The full report with the results and thermal model drawings is given below in the “CAD Drawings” section.

Non Standard Thermoblocks (made to order)

1. Marmox Thermoblock-PIR

To insulate beneath parapets or if bituminous membranes are being applied using a flame gun, Marmox Thermoblock-PIR, the flame resistant version must be used. These blocks are 53mm thick and available in 100mm and 140mm wide versions and are designed to be resistant to distortion that a flame gun might cause on the standard XPS version.

PLEASE NOTE: ‘Thermoblock-PIR’ is not stocked in the UK. It is made to order and therefore there is a 6 – 8 week lead time. Standard versions are always kept in stock but if you require this version you should order a couple of months in advance.

2. Marmox Thermoblock-100mm thick

Because building regulations in some countries in mainland Europe are more stringent than in the UK we make a 100mm thick version of Thermoblock (in all three widths). Although the standard 65mm thick version will virtually always be sufficient, these extra thick blocks provide an extra 33% more insulation.

PLEASE NOTE: ‘Thermoblock 100mm thick’ is not stocked in the UK. It is made to order and therefore there is a 6 – 8 week lead time. Standard versions are always kept in stock but if you require this version you should order a couple of months in advance.

Marmox – the thermal insulation experts

One of the easiest and most affordable ways to significantly cut the amount of energy used by a home, office building or public premises is by making use of effective insulation products – and the Thermoblock from Marmox is one solution that can certainly make a difference. Whether you’re interested in making a building more environmentally friendly, meeting regulations or simply cheaper to keep warm in the winter, Thermoblock could be the perfect solution to thermal bridging problems. In addition to the BRE accredited designs, we can offer a limited and basic thermal modelling analysis of your specific junction type.

Here at Marmox, we are experts in providing sustainable and cost-effective building products to construction and refurbishment professionals around the UK and Ireland. We supply the product both through the major nationals and through our independent stockists.