Irish Building Regulations: One National Rule Book on Chippy Tools

Ireland Wet-Area Waterproofing: What TGD Part C Doesn't Cover

Fri, 07 Aug 2026 00:00:00 +0000

The requirement

Straight answer: TGD Part C sets no wet-area waterproofing rule. There is no clause for a shower wall, a wet-room floor or a bath upstand. The working detail sits in two standards instead: BS 5385-1 and BS 8000-11, run through NSAI.

TGD C is called “Site Preparation and Resistance to Moisture”. The current edition is the 2023 amendment. It is the guidance to Part C of the Second Schedule to the Building Regulations 1997–2023. Like the UK version, it deals with the shell of the building. That means site prep, ground moisture, radon, and keeping rain out of walls and roofs. It never gets down to shower or wet-room floor detail. No membrane extent. No wall height. No tanking spec.

Irish Minimum Roof Pitch: What TGD Part C Doesn't Set

Fri, 07 Aug 2026 00:00:00 +0000

The requirement

TGD Part C sets no minimum roof pitch at all. Not for tile, not for slate, not for sheet. The current 2023 edition never states one. The word “pitch” does not appear in it. The real minimum comes from the product standard and the maker of your tile or slate.

TGD Part C is short for Technical Guidance Document C. Its full title is “Site Preparation and Resistance to Moisture”. It is the current guidance to Part C of the Building Regulations 1997, as amended. The 2023 edition is the one in force.

Does Ireland Have a Minimum Ceiling Height?

Fri, 07 Aug 2026 00:00:00 +0000

The requirement

Here’s the short answer: Irish Building Regulations set no minimum ceiling height for a dwelling. There is no single figure you are required to hit.

No fixed ceiling height. TGD Part F is the Technical Guidance Document for Ventilation. Its Diagram 3 (par. 1.2.1.7) shows heights: 2.4 m in general, 2.1 m at a beam or bay. Those numbers are real. But they are suggested guidance, not a rule.

Irish Ramp Gradients: TGD K & TGD M (Dwelling Approach)

Fri, 07 Aug 2026 00:00:00 +0000

The requirement

Ireland does not set one ramp number. It sets two, in two documents. TGD Part K caps a general ramp at 1:20, never steeper than 1:12 (par. 1.2.1). TGD Part M covers the approach to a new dwelling. Its bands: 1:20 up to 10 m, 1:15 up to 5 m, 1:12 up to 2 m (Table 2, par. 3.1.2.4).

So get the right document before you read off a gradient. Which one you need depends on what the ramp is for. Both use the same 1:20-to-1:12 range. But Part M ties the slope to how much run you have.

Irish Stair & Barrier Rules: Rise, Going, Handrails, Guarding

Fri, 07 Aug 2026 00:00:00 +0000

The requirement

For a private stair, each rise can be at most 220 mm, each going at least 220 mm (TGD K 2014, Table 1). The optimum is a 175 mm rise on a 250 mm going. The maximum pitch is 42°, with 35° the optimum (par. 1.1.4).

Two words to know. The rise is how tall each step is. The going is how deep it is, the flat part you stand on. These numbers come from TGD Part K, the Technical Guidance Document for Stairways, Ladders, Ramps and Guards. Its 2014 edition is the deemed-to-satisfy route under the Irish Building Regulations. Keep every step in a flight the same, so the stair climbs evenly.

Irish Strip Foundations: Widths, Depth & Concrete (TGD A)

Fri, 07 Aug 2026 00:00:00 +0000

The requirement

Ireland sets no fixed foundation depth. TGD Part A (par. 1.1.5.1–1.1.5.3) leaves the depth to your ground and your site investigation. Width does have numbers. Common soils land in a 400–650 mm band on TGD A’s strip foundation width table. The width can never be less than the wall width plus 75 mm on each side.

Depth: no frost rule, no fixed number. Unlike some countries, Ireland has no frost line to dig past. TGD A is the Technical Guidance Document for Structure. It is the deemed-to-satisfy route to Part A of the Building Regulations. Par. 1.1.5.1–1.1.5.3 sets the depth by the ground and the site investigation. There is no number on the page. What your report calls for is what you dig to. Any site that prints a single depth figure is guessing.