27 January 2016
A group of volunteers were involved in the process of waterproofing Tan y Bwlch roadbridge over the weekend of 24/25 January.
Before the work could start, contractors had erected scaffolding over the bridge. The rails, sleepers and ballast had been taken away to allow unfettered access to the bridge deck.
After the concrete was dry, a semi-transparent primer was applied. Being a two part chemical liquid, it was rapidly painted onto the surface of the concrete and worked into the gullies beside the ironwork. It dried within minutes. The brushes were rendered useless after use and had to be disposed of with care.
After a break for tea, the first coat of the white chemical water-proofer was applied. Again, the chemical reaction necessitated a speedy application, this time using squeegies.
Applying the second layer was just like icing a birthday cake but on a grand scale. To prevent boots contaminating the surface of the sealer, everyone has to stand on the protruding ironwork.
Being the final layer, it is essential to ensure that there are no pinholes or imperfections that would allow water penetration.
The Permanent Way gang are now able to return to reinstate the track.
In May we will return to paint the ironwork of the bridge (last done in 1986). This will again require scaffolding but, this time underneath. For safety reasons, that will require the road to be closed for a week.