'Refurbished Glass' for Refurbishing Old Floors


     “Our builder had never used the foamed glass material before but was pleasantly surprised how easy it was to lay and consolidate.  Also the thermal insulation benefits have been appreciated during the current winter period.”  Mr & Mrs K. (Northants, 2015)

TECHNOpor - warmth and strength in old buildings

TECHNOpor®, a pumice-like material, is lightweight but exceptionally strong.  When compacted, en masse, it forms a solid floor slab that is breathable, load-bearing and insulating – ideal within old buildings.  Each individual granule may appear somewhat insubstantial, but when locked in place as a solid floor slab, TECHNOpor® foam glass insulation has remarkable technical credentials:

Its certified compressive strength of 0.5N/mm² means that loads of 50tonnes/m² present no problem.  Importantly, the closed cell structure of the granules prevents moisture being drawn up by capillary action into the building structure; it negates the need for a damp proof membrane.   It is frost resistant, and has class-leading ‘Euroclass A1’ certification for fireproofing.  And, with a lambda value of 0.08 W/mK, it can deliver Passive House standards of insulation (the U value required determines the depth of TECHNOpor® used).

TECHNOpor® foam glass aggregate has been through rigorous testing as you would expect, and is certified as a load-bearing and insulating building material by the German construction authority, DIBt, and carries the CE conformity mark enabling it to be sold throughout Europe.  And it has LABC approval in the UK [see Technical Info page].

It compliments the use of lime in the renovation of old buildings as it is a breathable material.  There are now many examples in the UK of heritage buildings and barn conversions that have been restored with underfloor heating within a lime floor upon TECHNOpor® glass foam insulation (see below).

TECHNOpor - perfect beneath a lime floor

The building materials and techniques employed in old buildings were very different from those used today.  Modern buildings are weather proof and rigid; whereas older buildings were designed to breathe, absorbing moisture in wet conditions and releasing it back to the environment through evaporation when dry.  In order to work in harmony with this building ethos, lime – breathable and flexible – is often used today in the renovation and restoration of old buildings.

Likewise, lime floors can provide major benefits to older traditionally-built buildings when used as an alternative to DPM and cement concrete floors.  The use of breathable, flexible materials in the floor slab and screed eradicates differential movement between floor and walls, and prevents the concentration of moisture at wall junctions; with the inherent risk of rising damp.

TECHNOpor® glass foam insulation complements lime floor beautifully; TECHNOpor® offers the same breathability as lime, but adds the benefits of insulation and improved strength.


Heritage buildings and Barn Conversions

TECHNOpor® foam glass insulation has been used in the renovation of several ecclesiastical buildings, including Wakefield Cathedral (below) and St. Andrew’s Church in Gloucestershire (right).  It has been specified based on its suitability for old buildings (ability to breathe), allied to its compressive strength and thermal performance.  These buildings get a strong, insulating floor slab ready for underfloor heating and tiled floor / lime screed at a lower cost than the comparable concrete with foam insulation; and it works in harmony with the existing materials of the building.


   “We have now employed Technopor on six Grade 1 and Grade 2* medieval churches, where the Technopor has been installed as a base layer for a ground-bearing dry floor system with underfloor heating and a stone or tiled top surface. The Technopor has excellent insulating and load-bearing properties and has enabled us to install a load-bearing stone floor without pumping large quantities of wet lime concrete into an historically dry building. The Jupiter dry floor system, incorporating Technopor is incredibly quick to install and has a low impact on archaeology. We’re delighted with the ease and speed with which these projects have been implemented.”   John Minter Architect RIBA CA  [Lee Evans Partnership LLP, see Partners page]


Similarly, TECHNOpor® is fast becoming the floorslab material of choice in barn conversions (right).  A lime floor is ideal for barn conversions, and it makes no sense to sit a lime finish on a concrete slab; a breathable floorslab compliments the breathability of lime.  And the quickest, easiest and cheapest way to that breathable floor slab – that is both insulating and load-bearing – is to use TECHNOpor® glass foam aggregate.

In Summary - Renovation of old buildings using TECHNOpor

  • Breathable; ideal under a lime finish
  • Replaces traditional hardcore, blinding, oversite concrete and foam insulation
  • Capable of load-bearing 50tonnes/m²
  • Employed in Passive House construction because of its thermal performance
  • Sustainable building material, made from waste glass
  • Manufactured using hydro-electric power; low embedded carbon
  • Lightweight and non-toxic; safe and easy to handle and install
  • Frost and fire proof
  • No matrix or curing time; extremely quick to install
  • Can be laid in any weather conditions
  • Closed cell structure prevents moisture ingress due to capillary action
  • No deterioration over time, not susceptible to vermin or biological attack
  • Cost benefit due to price and speed of installation