Slate itself often lasts 80-150 years, but other roof components fail sooner. Here are the issues we fix most frequently on Dublin slate roofs.
Slipped or Missing Slates
Nail fixings corrode and fail over 60-80 years, causing slates to slip down or fall off entirely. This is the most common issue on Victorian and Edwardian slate roofs in Dublin. Wind and storms accelerate the problem.
Our Solution:
We carefully remove surrounding slates, replace damaged battens and felting if needed, and install matching replacement slates with stainless steel or copper fixings that won't corrode. Repairs blend invisibly with your existing roof.
Broken & Cracked Slates
Dublin's freeze-thaw cycles crack porous slates, especially lower-quality ones. Impact damage from falling branches or walking on roofs also causes cracks. Once cracked, water penetrates and the slate deteriorates rapidly.
Our Solution:
Individual broken slates are carefully removed and replaced with exact matches. If 20%+ of slates are cracked, we recommend complete re-slating with higher-quality slate that won't crack in Irish weather.
Valley Gutter Failures
Lead-lined valleys between roof slopes often fail after 40-60 years. Lead splits or corrodes, mortar bedding crumbles, and debris accumulation causes overflow. Valley leaks cause significant interior water damage.
Our Solution:
We strip valley slates, remove old lead/mortar, install new Code 5/6 lead properly bedded, and re-slate with correct overlap. Properly rebuilt valleys last 60+ years. We also install leaf guards if trees overhang.
Chimney Flashing Problems
Lead flashings around chimneys deteriorate, mortar joints fail, and stepped flashings pull away from brickwork. This is a prime leak source on period Dublin properties, especially after storms.
Our Solution:
We install new stepped lead flashings properly dressed into raked-out brick joints, weathered correctly, and with adequate overlap onto slates. All work complies with modern building standards whilst preserving period appearance.
Ridge Tile Movement & Failure
Mortar bedding under ridge tiles fails after 30-50 years, causing tiles to become loose or fall. This allows wind-driven rain into the roof space and accelerates batten deterioration.
Our Solution:
We remove old ridge tiles and failed mortar, install modern dry ridge systems (mechanically fixed, maintenance-free) or properly bed ridge tiles in fresh mortar depending on property requirements and planning restrictions.
Structural Timber Deterioration
Years of minor leaks rot battens, rafters, and valley boards. This is often discovered only when slates are removed for repairs. Rotten timber cannot support new slates properly.
Our Solution:
Our team includes experienced carpenters who can replace damaged battens, splice in new rafter sections, or rebuild entire valleys. We never hang expensive new slates on rotten timber - it's a recipe for failure.
