How to Set Up Heat Lamps and UVB Lighting in a Wooden Tortoise Enclosure

White and grey wooden tortoise enclosure with an attached adjustable heat lamp stand in a sunlit interior

A wooden tortoise enclosure needs two kinds of light, and each kind needs its own fitting. A heat lamp makes a warm basking spot at one end, so the tortoise can choose between warmth and a cool retreat.^[1] A UVB tube gives the ultraviolet light that helps the tortoise absorb calcium and make vitamin D3.^[1] Both fittings need a reflector and a safe hanging height, any heat source needs a thermostat, and everything must be fixed where the tortoise cannot touch it.^[1]^[2]

The fixings are simple. The heat lamp hangs from an overhead batten or a hanging chain, and the UVB tube clips to the inside walls, so no external stand is needed. Follow these six steps in order:

Plan the layout and temperature gradient.
Choose a mount and route the cables.
Fit the heat lamp, guard and thermostat.
Set the heat lamp height.
Fit the UVB tube and set its height.
Check the setup every week.

Step 1: Plan the Layout and Temperature Gradient

Hand placing a basking slate inside a wooden tortoise table alongside layout plans and temperature notes

Heat and UVB do different jobs, so plan where each one goes before you fix anything. A safe setup reads as a simple map, with heat at one end and shade at the other.

Heat lamp: At one end above the tortoise table, so the tortoise can choose where it feels most comfortable within the heat gradient.^[1]
Basking area: Under the heat lamp, with the UVB tube overhead on the warm side.
Hide: At the cooler end, away from the heat.
Food and water: Away from the hottest spot, so the tortoise does not have to stand under the lamp to eat or drink.
Thermometers: One at each end, so you can see whether the gradient is real or only assumed.^[1]

Then check what each light has to deliver:

Temperatures: Around 32°C at the hot end and around 20°C at the cool end, with a night temperature near 18°C.^[1] A separate guide gives a basking spot of 35°C, daytime temperatures of 20°C to 25°C and a night drop to 15°C.^[3]
UVI range: A veterinary sheet gives a UV Index (UVI) gradient from 0 in full shade to 9.5 across the enclosure.^[1]
Species maximums: Partial sun baskets, such as Hermann’s, Egyptian and Greek spur-thighed tortoises, have a maximum UVI of 7.4 at the basking spot. Marginated tortoises, as mid-day sun baskets, have a maximum UVI of 9.5.^[1]

Step 2: Choose a Mount and Route the Cables

Hand using a screwdriver to secure a black cable clip onto a wooden tortoise enclosure wall

Four fixings suit most wooden tables, and each can be set up so the lamp height is adjustable.

Overhead batten: A timber batten fixed across the top of the table carries the heat lamp holder on its underside.
Inside wall clips: Clips or brackets on the side walls hold the UVB tube inside the enclosure, with no glass or plastic between the bulb and the tortoise.
Hanging chain: A short chain from a ceiling hook or a table frame lets the heat lamp rise or fall in small steps.
Clamp and bracket: A clamp lamp with a vivarium bracket grips the table edge and holds the lamp over the basking spot.

Wiring should leave the enclosure as soon as it can:

Route: Run cables out through the top or the back, clip them to the outside of the timber, and keep the plug and socket outside the table.
Inside: No loose cable should hang inside, where it can be chewed, climbed or pulled. Keep cables away from the water dish.
Timer: Keep the timer and thermostat readable without moving the lamps. A timer can give a steady 10 to 12 hours of light each day, with darkness at night.^[1] The RSPCA gives 12 to 14 hours depending on the season, so choose a day length that suits your tortoise and keep it steady.^[3]

Step 3: Fit the Heat Lamp, Guard and Thermostat

Hands using a screwdriver to install a heat lamp with a wire guard inside a wooden enclosure

Timber protection is part of the fitting, so fix each part in this order.

Holder: Choose a ceramic holder rated at or above the bulb wattage, and check the rating printed on the holder before fitting.
Guard: Cover the bulb with a guard and hang the lamp out of reach, so the tortoise cannot touch it.^[1]
Dome: Point the dome down toward the basking spot, not up into the wooden top.
Air gap: Leave an air gap between the hot holder, the dome and the wood, and never rest a lamp directly on timber. Look at the wood around each fitting once a month, and move or refit anything that shows darkening.
Thermostat: Control the intensity of the heat source with a thermostat, so a hot day or a closed room is less likely to push the basking spot too high.^[1] A dimming thermostat suits a basking lamp, and a pulse thermostat suits a ceramic heater.^[4]
Night heat: Keep heat and light sources separate, so the lights can stay off overnight. A tortoise table inside a heated home may need no lighting or heating at night.^[2]

Step 4: Set the Heat Lamp Height

There is no fixed height for a heat lamp, as the correct distance depends on its wattage and table size.

Use a thermometer rather than a ruler. Start with the lamp higher, then lower it gradually until the basking spot reaches 32°C to 35°C at shell height.^[1]^[3] If it is too hot, raise the lamp. If it is too cool, lower it in small steps and recheck. Suspend the lamp high enough to prevent contact burns.^[1]

Step 5: Fit the UVB Tube and Set Its Height

Tortoise basking under a heat lamp next to a UVB tube fixture and digital thermometer inside a wooden habitat

A UVB tube is set by the distance table for the exact lamp, not by guesswork.

Mount the tube directly overhead and fit the reflector that comes with the fitting, which directs the light down toward the tortoise.^[2] Cover the bulb with a guard as well, which helps prevent burns. Keep the fitting out of the tortoise’s line of sight, because a lamp clamped to the side shines directly into the eyes and can damage vision.^[2]

Keep glass and plastic covers out of the beam, because they block UVB before it reaches the shell. Mesh also reduces the output, so if a mesh top must stay, expect lower UVB below it and set the height with the mesh in place. The maker of the lamp below notes that its extra energy helps light penetrate deeper into enclosures with a mesh top.^[5]

Distance from a 14% T5 lamp to the shell	UV Index (UVI) directly below the lamp
300 mm	Not advised
380 mm	7.00
450 mm	5.50
500 mm	4.60
600 mm	3.20

Source: maker’s distance table for the 14% T5 lamp, shown as the maximum directly under the lamp.^[5]

The table shows why distance is a setting, not a detail. For this lamp, the UVI falls from 7.00 at 380 mm to 3.20 at 600 mm, so a change of about 20 cm in height can move the tortoise from well above the target range to inside it.^[5] For a different lamp, use its own table, because output differs by lamp type and strength.

As a rough guide for one maker range, a fixture 30 cm to 40 cm above the shell suits a 6% tube, and a fixture 40 cm to 60 cm above the shell suits a 12% tube.^[6] Hermann’s tortoises are generally kept at a UVI between 3 and 4, and the distance that achieves this differs between brands of mercury vapour lamp.^[6] Where doubt remains, a Solarmeter reading at the basking spot confirms the height.^[1]

Step 6: Check the Setup Every Week

A five-minute weekly check catches most lamp problems before they harm the tortoise or the timber.

Weekly check	What good looks like
Basking temperature	32°C to 35°C at shell height.^[1]^[3]
Cool end temperature	Around 20°C, so the tortoise can retreat from heat.^[1]
Guard and holder	Guard fixed, holder firm, no darkening on nearby timber.
Cables	Clipped outside, none loose inside, plug dry.
UVB bulb age	Dated at fitting, inside the maker’s stated life.^[2]^[5]
Timer	Light on for the chosen day length, darkness at night.^[1]

Bulb age deserves its own note, because two figures exist. The Tortoise Protection Group advises replacing UVB tubes after about 6 months, or 12 months for a 10% tube.^[2] Arcadia states a 12 month lifespan for its T5 lamps before a change is required.^[5]Follow the figure for the lamp type fitted, and date every bulb when it goes in. UV output decreases over time, so a glowing bulb is not proof of ultraviolet output.^[1]

What Setup Mistakes Cause Scorching or Cold Spots?

Infographic outlining seven common setup mistakes when installing heat lamps and UVB lighting

Most lamp problems come from one of seven fitting mistakes, and each one is easy to spot.

Lamp touching timber: A lamp that rests on wood, or hangs too close to it, can scorch the surface over time. Leave an air gap, and use a dome that points the heat down.
No guard: An unguarded bulb can burn a tortoise that reaches or climbs toward it.
No thermostat: A heat source without a thermostat can overheat a closed wooden enclosure, and a mercury vapour lamp cannot be controlled by a thermostat, so it is likely to overheat in an enclosed set-up.^[1]^[6]
Furnishings under the lamp: A hide or rock under the lamp can leave the tortoise overturned beneath the heat source.^[1]
Mesh or glass in the way: Glass and plastic block ultraviolet, and mesh reduces it, so the height that worked in open air no longer gives the target UVI. Set the height with any guard or mesh in place.
No thermometer: A setup judged by eye can run too hot or too cold for weeks, while a thermometer at each end shows the gradient at once.^[1]
Old UVB bulb still glowing: UV output decreases over time, so a bulb that still glows can give little ultraviolet.^[1] Date every bulb when fitted, and replace it at the end of the maker’s stated life.^[2]^[5]

FAQs

1. Can a heat lamp sit directly on a wooden table top?

No. A heat lamp should hang from a holder with an air gap above the timber. A guard should stop the tortoise touching the bulb, and the lamp should hang high enough to prevent burns.^[1] Point the dome towards the basking spot, and use a thermostat to prevent overheating.^[1] Check the wood around the fitting monthly for darkening.

2. How do I know if the UVB tube is at the right height?

Follow the distance table for the exact lamp, measuring from the bulb to the tortoise’s shell at the basking spot.^[5] For example, a 14% T5 lamp gives a UVI of 7.00 at 380 mm and 3.20 at 600 mm.^[5] Aim for the right UVI for the species, such as 3 to 4 for Hermann’s tortoises.^[6] Use a Solarmeter for a reading where available.^[1]

3. Does mesh over the table block UVB?

Mesh can reduce the UVB reaching the tortoise, so mount the tube inside the enclosure without anything in the way where possible. One maker notes that extra lamp energy helps light penetrate deeper into enclosures with a mesh top.^[5] If mesh must remain, check the UVB level at the basking spot with a Solarmeter.^[1]

4. Can one bulb give both heat and UVB?

Yes. Mercury vapour and metal halide lamps provide both heat and UVB.^[1] However, mercury vapour lamps cannot be controlled by a thermostat, which raises the risk of overheating in an enclosed setup.^[6] In a vivarium, heat and UVB should come from separate sources, with the heat source on a thermostat.^[4][6]