Oatey Shower Drains: Complete Guide to Models & Installation UK 2025

I’ll never forget the call I got last year in a Victorian terrace in Bristol. The homeowner had installed a cheap plastic shower drain themselves, convinced it would save time and money. Within six weeks, water was seeping through the floorboards into the flat below—£3,200 in damages, not including the emotional toll. That’s when I realised how critical the right oatey shower drain is, especially in the UK’s often damp, uneven subfloors and strict building regulations. As a licensed plumber with 12+ years of experience and NICEIC Part P certification, I’ve installed hundreds of Oatey drains across London, Manchester, and Edinburgh. Whether you’re renovating a period property or building a new bathroom, choosing the correct Oatey model, using the right tools, and following UK-compliant installation methods can mean the difference between a watertight seal and a costly flood.

This comprehensive guide consolidates everything you need to know about Oatey shower drains in the UK—from popular models like the 39148, 42099, and the innovative Casper system, to brass versus plastic comparisons, gasket selection, and step-by-step installation. I’ll share real-world case studies, exact measurements, supplier pricing (as of early 2025), and troubleshooting tips based on actual jobs. For comprehensive shower drain installation procedures, see our complete installation guide. Whether you’re a DIY enthusiast or a professional tradesperson, this article will equip you with the knowledge to install an Oatey drain that lasts decades—not months.

Quick Steps: Installing an Oatey Shower Drain (UK)

1. Confirm floor depth and waste pipe alignment (min. 85mm clearance).
2. Choose brass (for longevity) or ABS plastic (for budget) based on subfloor type.
3. Select the correct gasket (EPDM for wet rooms, neoprene for timber floors).
4. Use the Oatey drain wrench (model 39000) for secure, leak-free assembly.
5. Test with 15 litres of water before tiling—check for leaks at the compression joint.
6. Comply with UK Building Regulations Part G (sanitation) and Part H (drainage).

Oatey Shower Drain Models: 39148, 42099, 42237 & Casper Explained

Oatey offers a range of shower drain models tailored to different floor constructions, finishes, and performance needs. In the UK market, four models dominate professional and DIY installations: the 39148, 42099, 42237, and the newer Casper system. Each has distinct features that make it suitable for specific scenarios—knowing which one to choose is half the battle.

Oatey 39148: The Workhorse for Concrete Floors

The Oatey 39148 is a brass-bodied, adjustable-height shower drain designed primarily for concrete slab installations. I’ve used this model extensively in new-build apartments across Manchester and Birmingham, where poured concrete floors require a robust, watertight connection. The 39148 features a 2-inch (50mm) outlet, compatible with standard UK waste pipes, and an adjustable height range of 85–120mm—critical for achieving the correct fall towards the drain without compromising floor finish thickness.

One key advantage is its integrated weep holes and compression seal design, which prevent hydrostatic pressure buildup under tiles—a common cause of tile failure in wet rooms. At Screwfix, the 39148 retails for £67.99 (as of March 2025), while B&Q lists it at £72.50. Always verify stock, as lead times can stretch to 10 days during peak renovation seasons.

Oatey 42099: Ideal for Timber Joist Floors

For suspended timber floors—common in older UK homes—the Oatey 42099 is my go-to choice. This ABS plastic drain includes a flexible rubber gasket and a clamping ring that compresses against the subfloor, creating a seal even on slightly uneven surfaces. I once replaced a failing drain in a 1987 bungalow in Brighton where the joists had sagged by 8mm; the 42099’s flexibility accommodated the variance without leakage.

The 42099 also features a reversible strainer (chrome or brushed nickel finish) and a 2-inch solvent weld outlet. It’s lighter than brass models, making it easier to handle during installation, but less durable long-term in high-traffic commercial settings. Priced at £48.75 at Toolstation and £52.00 at Travis Perkins, it’s a cost-effective solution for residential retrofits.

Oatey 42237: The Universal Adapter

The Oatey 42237 isn’t a full drain but an adapter kit that converts existing 2-inch waste openings to accept Oatey’s universal flange system. I used this in a listed cottage in Bath where altering the original cast-iron waste pipe wasn’t permitted. The 42237 allowed me to install a modern Oatey strainer and seal without major structural changes.

It includes a stainless steel flange, EPDM gasket, and fasteners. At £34.99 from specialist supplier Plumbworld, it’s a niche but invaluable product for heritage renovations. Always check compatibility with your existing pipe diameter—UK standards typically require 50mm internal diameter.

Oatey Casper Shower Drain System: The Future of Wet Room Drains

Introduced in 2023, the Oatey Casper system revolutionises linear drainage in UK wet rooms. Unlike traditional point drains, Casper uses a sleek, low-profile channel (available in 600mm, 900mm, and 1200mm lengths) that integrates seamlessly with large-format tiles. I installed a 900mm Casper in a London penthouse last autumn—the client wanted a minimalist look with zero visible screws or grates.

The Casper system includes a pre-sloped stainless steel channel, adjustable legs for precise levelling, and a hidden clamping mechanism that secures the tile edge without adhesives. It meets UK Building Regulation Part H3 for surface water drainage and is ideal for level-access showers. However, it requires a minimum floor depth of 110mm and careful waterproofing (use a certified tanking membrane like Mapei Mapelastic). At £189.00 for the 900mm kit (Toolstation), it’s a premium option—but worth every penny for high-end projects.

Brass vs Plastic Oatey Drains: Which Is Right for Your UK Project?

The choice between brass and plastic (ABS) Oatey drains isn’t just about cost—it’s about longevity, compatibility, and compliance with UK building standards. Having installed both types across hundreds of jobs, I can confidently say each has its place.

Brass drains (like the 39148) offer superior corrosion resistance, especially in areas with hard water—common in Kent, Yorkshire, and the Midlands. They’re also less prone to cracking under tile adhesive pressure. In a commercial gym in Leeds, I replaced six plastic drains that had shattered within two years; switching to brass extended service life to over eight years.

Plastic drains (like the 42099) are lighter, cheaper, and easier to cut or modify on-site. They’re ideal for DIYers or temporary installations. However, they can degrade under prolonged UV exposure (rare indoors but possible in glass-walled showers) and may warp in high-humidity environments if not properly supported.

For most UK homes, I recommend brass for concrete floors and plastic for timber—unless the budget allows for brass everywhere. Always ensure your choice complies with Part G of the Building Regulations, which mandates durable, hygienic materials in wet areas.

Step-by-Step: Installing an Oatey Shower Drain in the UK

Proper installation is non-negotiable. A poorly fitted Oatey drain will fail—no matter how expensive the model. Below is my field-tested method, aligned with UK best practices.

Preparation & Measurements

First, confirm the waste pipe location using a laser level. The drain must align within ±3mm. Measure floor depth from the subfloor to the finished tile surface—most Oatey models require 85–120mm. In a recent job in Glasgow, I discovered the builder had poured the concrete 15mm too high; we had to grind down the slab to avoid a raised drain.

Cutting the Opening

Use a diamond hole saw (68mm for most Oatey flanges) to cut through tiles and substrate. For timber floors, drill pilot holes at corners and use a jigsaw with a fine-tooth blade. Always wear PPE—dust masks and goggles are essential.

Assembling the Drain

Apply a bead of silicone sealant (use a neutral-cure type to avoid damaging ABS) to the underside of the flange. Insert the drain body into the waste pipe and tighten the compression nut using the Oatey wrench (more on that below). Do not overtighten—this can crack plastic components.

Water Testing

Before tiling, pour 15 litres of water into the drain and wait 30 minutes. Check for leaks at the joint and under the floor. If water appears, disassemble and reseal. Never skip this step—I’ve seen tilers blame cracked grout when the real issue was a leaking drain.

⚠️ Warning: Never install an Oatey drain without a compatible waterproof membrane. In the UK, BS 5385-3 requires tanking systems in wet rooms. Failure to comply voids warranties and breaches Part H of the Building Regulations.

Oatey Drain Wrench Tool Guide: Why the 39000 Is Essential

The Oatey drain wrench (model 39000) isn’t optional—it’s critical for achieving the correct torque on compression fittings. I keep three in my van at all times. Generic adjustable wrenches often slip or strip the nut, leading to leaks.

The 39000 features a non-marring nylon jaw that grips the nut without scratching chrome finishes. It’s designed specifically for Oatey’s 2-inch drains and provides the leverage needed to compress the gasket fully. At £24.99 from Screwfix, it pays for itself in avoided call-backs.

For Casper systems, Oatey also offers a specialised alignment tool (model 42050, £18.50) that ensures the channel is perfectly level before fixing. I used this on a luxury hotel project in Edinburgh—without it, the water pooled at one end.

Selecting the Right Oatey Gasket: EPDM, Neoprene & More

The gasket is the unsung hero of any shower drain. Choose wrong, and you’ll be back on-site within months. Oatey offers several gasket types, each suited to specific conditions.

EPDM gaskets: Best for wet rooms and concrete floors. Resistant to mould, ozone, and temperature swings. Use with the 39148.
Neoprene gaskets: Ideal for timber floors where slight movement occurs. More flexible than EPDM. Standard on the 42099.
Silicone gaskets: Used with Casper systems for seamless integration with linear channels.

Always check the gasket’s temperature rating—UK building codes require materials stable from -10°C to +60°C. Avoid cheap aftermarket gaskets; I once traced a leak in a Newcastle flat to a recycled rubber gasket that hardened in winter.

UK Availability & Suppliers: Where to Buy Oatey Drains in 2025

Oatey products are widely available across the UK, but stock levels vary. Here’s my 2025 supplier breakdown:

Screwfix: Stocks 39148 (£67.99), 42099 (£48.75), and 39000 wrench (£24.99). Next-day delivery in most areas.
Toolstation: Carries 42099 (£48.75) and Casper kits (£189.00). Good for trade accounts.
B&Q: Limited Oatey range (mainly 39148 at £72.50), but useful for DIYers.
Plumbworld & Travis Perkins: Best for specialist items like the 42237 adapter (£34.99).

Always order spare gaskets—they’re often out of stock when you need them most.

Troubleshooting Common Oatey Drain Issues

Even with perfect installation, problems arise. Here’s how I diagnose and fix them:

Slow drainage: Usually caused by a blocked weep hole. Use a wire brush to clear debris.
Gurgling sound: Indicates improper venting. Check if the waste pipe connects to a soil stack with adequate airflow.
Water under tiles: Likely a failed gasket or insufficient compression. Reinstall with a new EPDM gasket.

Maintenance & Cleaning Tips for Long-Term Performance

Clean your Oatey drain monthly with a vinegar-water solution (1:1 ratio) to dissolve limescale—common in hard water areas like London. Avoid harsh chemicals like bleach, which degrade rubber gaskets. For Casper channels, use a soft brush to remove hair and soap scum from the grate slots.

Oatey vs UK Brands: FloWise, Hunter & Others

How does Oatey stack up against local favourites? The FloWise 10235 (£58 at Toolstation) is a decent plastic alternative but lacks adjustable height. Hunter Plastics offers cast iron drains (£95+) that are overkill for most homes. Oatey strikes the best balance of quality, compliance, and availability—especially with its UK-compliant Part H certification.

Frequently Asked Questions (FAQs)

Q: Can I install an Oatey drain in a shower tray?
A: No. Oatey drains are for direct-to-floor installations only. Use a tray-specific waste instead.

Q: Are Oatey drains compatible with UK 50mm waste pipes?
A: Yes—all standard Oatey models use 2-inch (50mm) outlets, matching UK plumbing norms.

Q: Do I need a plumber to install an Oatey drain?
A: Not necessarily, but if you’re unsure about waterproofing or pipe alignment, hire a Part P-certified professional.

Q: How often should I replace the gasket?
A: Every 5–7 years, or sooner if you notice leaks or hardening.

Q: Can the Casper drain be used outdoors?
A: No—it’s designed for indoor wet rooms only.

Q: Is the Oatey 39148 suitable for underfloor heating?
A: Yes, but ensure the heating cables avoid the drain body by at least 100mm.

Q: What’s the warranty on Oatey drains?
A: 10 years on brass models, 5 years on plastic—when installed per instructions.

Q: Can I use PTFE tape on Oatey compression fittings?
A: No—compression seals rely on gasket compression, not thread sealing.

Q: Are Oatey drains recyclable?
A: Brass models are fully recyclable; check local facilities for ABS plastic.

Q: Do Oatey drains meet UK building codes?
A: Yes—they comply with Part G (sanitation) and Part H (drainage) when installed correctly.

Final Thoughts from a UK Plumber

After a decade of installing shower drains across the UK, I can say with certainty: oatey shower drain systems offer unmatched reliability when matched to the right application. Whether you’re choosing the robust 39148 for concrete, the flexible 42099 for timber, or the sleek Casper for modern wet rooms, success hinges on proper preparation, correct gasket selection, and adherence to UK regulations. Don’t cut corners—your floors (and your reputation) depend on it.

For more expert guidance, explore our wet room waterproofing guide, Part H drainage regulations explainer, and shower tray vs wet room comparison.

About the Author
Jennifer Walsh is a licensed plumber with over 12 years of experience servicing residential and commercial properties across the UK. Holding NICEIC Part P certification, she specialises in bathroom renovations, wet room installations, and compliance with UK Building Regulations. Jennifer regularly contributes expert advice to AnswerEye.com, helping homeowners and tradespeople navigate complex plumbing challenges with practical, code-compliant solutions.