Restoration of Historic Portland Stone Floors at Leinster House

Restoration and conservation of Historic Portland stone floors at Leinster House

Client: Duggan Brothers Contractors Limited for OPW

The Portland stone floors in Leinster House are original to the building. The overall conservation strategy was to place the emphasis on repair and conservation of the historic fabric of the building rather than replacement. We therefore carried out repairs to stones wherever possible and only replaced with new stone where absolutely necessary. 

Floors were cleaned and stripped to expose extent of repairs. 

All damaged stones were carefully removed for replacement or repair. These were all numbered and stored. Existing stone was repaired to best colour match and new replacement stones were used only where repair was not feasible.

Chipped corners, gouges and dips were repaired with stone indents and original left over matching stone. 

Once all repairs were complete we repointed all joints with sand and lime mortar.

Floors were finally sealed with a breathable sealant.  

reception area of Leinster house

Sealing marble and stone floors

Stone is naturally porous; any liquid spilled on unsealed stone will seep into the stone and stain. By sealing the stone, you effectively seal the pores. This prevents the spill soaking into the stone, leaving it on the surface where it can be cleaned up. Spills should be cleaned up as soon as possible, as they can penetrate if left.

Polished natural stone reflects light and does not need a topical coating or wax to achieve a high gloss finish. We recommend sealing with a topical seal on heavily trafficked floors in commercial environments, or on travertine, quarry or terracotta tiles due to their highly porous nature.

Stone sealers break down in the presence of UV light, when cleaned with harsh cleaners or because of general wear. It is therefore recommended that you re-seal your stone every two to three years.

Heritage Contractors

Pmac projects are very varied. Our legacy is quality projects we can be proud of and the below projects are an example of them. We value the inputs of our customers, our team and our supply chain in reaching positive outcomes. Health and safety to our people and the public is a priority for us and without compromise.

If you are working on a similar project we would love to hear about it. Dont hesitate to call us or send in the details of your project through our contact page at

PMAC is a registered Heritage Contractor and a link for the site can be found below.

The majority of Pmac projects are based in Dublin but we also work all over Ireland. Our wide range of services are available to both residential and commercial clients.