Diy: Painting A Skylight Shaft Above Your Tub

Painting a skylight shaft above a tub can be a challenging task, requiring careful consideration of paint type, colour, and insulation. The moisture in bathrooms can cause condensation on the skylight glass, leading to issues with drywall and moulding. To prevent this, some homeowners install a picture frame-type moulding around the shaft opening, allowing for airflow while darkening the room. Others suggest using spring bars to support material spread across the skylight frame, such as bubble wrap for insulation. When it comes to paint selection, the skylight shaft's exposure to sunlight and UV rays must be considered, requiring a stronger paint that can withstand high UV exposure and heat. Oil-based paints, latex paints, and ceiling paints are all options mentioned, with some opting for unique colours to create a glowing effect.

Paint selection

Painting a skylight shaft above a tub requires careful paint selection to ensure the paint is durable and suitable for the space. Here are some factors to consider when choosing the right paint for the job:

• Sunlight and UV Exposure: Skylight shafts are exposed to high levels of sunlight and UV rays. Therefore, it is essential to choose a paint that can withstand these conditions without fading or deteriorating. Look for paints specifically designed to resist UV rays and high temperatures.
• Moisture and Condensation: The presence of a tub or shower in the room can lead to increased moisture and condensation on the skylight and its shaft. Select a paint that is suitable for humid environments and can resist moisture to prevent issues like peeling or mould. Oil-based paints or latex paints are often recommended for their durability and moisture resistance.
• Surface Preparation: Properly preparing the surface before painting is crucial. Ensure the surface is clean, dry, and primed. If there is existing paint, primer, or drywall, check for any damage or peeling. Repair and prime the surface before applying paint.
• Colour and Light Reflection: The colour of the paint can significantly impact the light coming through the skylight shaft. Consider the desired effect and how different colours may interact with the light. Light colours, such as white, can help reflect light and brighten the space. Darker colours may reduce the amount of light entering the room. Additionally, consider the colour scheme of the surrounding area to ensure the paint colour complements the overall aesthetic.
• Type of Paint: The type of paint you choose depends on the surface you are painting and the desired finish. Ceiling paint is an option for skylight shafts, especially if it is a flat interior paint designed to withstand high UV exposure. You can also consider wall paint for the skylight shaft walls if you want a different finish or colour. However, ensure that the paint is suitable for the specific surface, such as drywall or wood.
• Durability and Maintenance: Select a paint that is known for its durability and longevity, especially in humid and sunny environments. Consider the maintenance requirements of the paint and whether it will need frequent re-painting or touch-ups. Choose a paint that is easy to maintain and can withstand the test of time.

When selecting paint for a skylight shaft above a tub, it is essential to consider factors such as sunlight exposure, moisture resistance, surface preparation, colour, and the type of paint suitable for the surface. By choosing a durable and suitable paint, you can enhance the lighting and aesthetic of the space while ensuring the paint job lasts for years to come.

Insulation and ventilation

When installing a skylight above the tub, it is important to consider insulation and ventilation to prevent condensation and heat damage.

Firstly, the skylight shaft should be insulated to prevent heat loss and condensation issues. One option is to use spray foam insulation, which is less labour-intensive and has fewer potential issues compared to other methods. The skylight shaft can be spray-foamed by a professional insulation contractor, or you can do it yourself with a DIY kit. This method ensures that the shaft is airtight, preventing warm air from escaping during the winter.

Another option for insulation is to use rigid foam, which comes in three main types: extruded polystyrene (XPS), expanded polystyrene (EPS), or polyisocyanurate. The thickness of the rigid foam will depend on the climate zone you are in. For colder regions, a thicker layer of rigid foam is required to keep the stud cavities above the dew point in winter. For example, in northern Minnesota or Maine, at least 3 inches of rigid foam are needed, whereas in warmer zones, the thickness is less of a concern. All rigid-foam seams should be sealed with caulk, canned spray foam, or high-quality tape.

Additionally, the skylight shaft walls should be insulated to the same R-value as other exterior walls. The higher the R-value of the insulation, the better. Rigid foam is preferable to fiberglass batts, as it raises the overall R-value of the assembly and is less likely to sag or pull away from the wall.

To further enhance insulation and ventilation, you can install a picture frame-type moulding around the bottom of the shaft opening, allowing it to overhang by about half to three-quarters of an inch. Then, you can place a piece of plexiglass or plastic cut to fit the shaft size, which will be held in place by the moulding. This setup prevents warm, moist air from reaching the cold glass and condensing, reducing the potential for condensation issues.

Finally, to address ventilation specifically, it is recommended to install an exhaust ventilation fan near the top of the skylight shaft, which can help to alleviate condensation problems.

Priming the surface

Prepare the Surface:

Before priming, ensure that the surface is clean and free of any dirt, dust, or debris. If there is existing paint, make sure it is intact and properly adhered to the surface. If there are any flaking or peeling areas, scrape and sand the surface to create a smooth base. It is crucial to address any signs of water damage or condensation, as mentioned in your previous message, by ensuring the area is dry and repairing any damage.

Choose the Right Primer:

Selecting the appropriate primer is essential. Since the skylight shaft will be exposed to significant sunlight, heat, and moisture due to its location above the tub, opt for a primer that can withstand these conditions. Look for a primer that is specifically designed for high UV exposure and moisture resistance. Oil-based primers are a good option, as they provide a durable base and can better withstand moisture and heat.

Apply the Primer:

Follow the instructions on the primer product you have chosen. Typically, you will use a brush or roller to apply the primer, ensuring even coverage across the entire surface of the skylight shaft. Pay close attention to the edges and corners, ensuring that they are adequately primed. Allow the primer to dry completely according to the manufacturer's instructions before proceeding to the next step, which is painting.

Sand the Primed Surface (Optional):

Depending on the desired finish and the type of paint you intend to use, you may want to lightly sand the primed surface to create an ultra-smooth base for the paint. This step is especially important if you plan to use a high-gloss paint, as it will help achieve a flawless, streak-free finish.

Clean Up:

Lastly, before moving on to the painting stage, ensure that you properly clean and store your tools and that any spills or drips are addressed to avoid unwanted stains.

Remember, priming the surface is a critical step in ensuring the longevity of your paint job and protecting the skylight shaft from the elements.

Painting techniques

Painting a skylight shaft above a tub can be a challenging task due to the unique lighting conditions and the potential impact of moisture. Here are some techniques and considerations to help you achieve the desired results:

Priming and Painting:

Before painting the skylight shaft, it is essential to prepare the surface properly. If you have newly installed plasterboard or drywall, prime the surface before applying a topcoat of paint. Priming will help the paint adhere better and create a more uniform finish. Allow the primer to dry completely before proceeding to the next step.

Paint Selection:

The paint you choose for the skylight shaft should be able to withstand high UV exposure and heat. Consider using a stronger paint designed for exterior use or a paint that can handle intense sunlight without fading or discolouring. Ceiling paint can be used, but it may not be durable enough for the skylight shaft, which is exposed to more sunlight. You can use Taubmans Tradex White Flat Interior Ceiling Paint, which is suitable for skylight alcoves, ceilings, and cornices. However, keep in mind that ceiling paints are typically not supplied in sample pots, so consider doing a test section first to ensure you are happy with the colour.

Protecting from Moisture:

If your skylight is located in a bathroom with a tub or shower, you must address the issue of moisture. Condensation can form on the glass and run down the shaft, causing issues with drywall and moulding. To prevent this, consider installing a picture frame-type moulding around the bottom of the shaft opening, allowing the moulding to overhang by about 1/2 - 3/4". Then, drop in a piece of plexiglass or plastic cut to fit the shaft size. This will hold the plexiglass in place and prevent warm, moist air from coming into contact with the cold glass and causing condensation.

When painting the skylight shaft, use steady and consistent strokes. Ensure the paint is applied evenly to avoid any patchy areas. Pay attention to the corners and edges of the shaft, as these areas may require more precise brushwork. It is recommended to apply at least two coats of paint for a durable and consistent finish.

Experiment with Lighting Effects:

The lighting effects in a skylight shaft can be unique due to the polarization of light. Consider experimenting with different paint colours and finishes to achieve the desired effect. For example, a semi-shiny satin paint can reflect light back upon itself, intensifying certain tones. You can also play with colour opposites on the colour wheel to create interesting visual impacts, such as pairing an aqua shade with orange wood tones.

Remember to take the necessary safety precautions when working at heights and follow the instructions provided by the paint manufacturer for drying times, ventilation, and surface preparation.

Maintenance and care

When it comes to maintaining and caring for a painted skylight shaft above the tub, there are several important considerations to keep in mind. Firstly, due to the high moisture levels in bathrooms, condensation can form on the glass of the skylight and run down the shaft, potentially causing issues with drywall and moulding. To mitigate this, consider installing a picture frame-type moulding around the bottom of the shaft opening, allowing it to overhang by about 1/2 to 3/4 inch. Then, drop in a piece of plexiglass or acrylic cut to fit the shaft size, which will be held in place by the moulding. This will prevent warm, moist air from coming into contact with the cold glass and causing condensation.

Additionally, it is crucial to select the appropriate paint type for the skylight shaft to ensure its longevity. The shaft will be exposed to significant sunlight, UV rays, and heat, so it is recommended to use a stronger paint that can withstand these conditions. Latex paint, for instance, can serve as a vapour barrier. Oil-based paints are also an option, but they may not offer more protection than latex. If you want to reflect more light, consider using a non-specular (not glossy) white or aluminium paint. However, keep in mind that materials like aluminium foil and aluminized Mylar have higher reflectance than white paint.

To enhance the insulation of the skylight shaft, you can frame, insulate, and air seal the walls as you would with an exterior wall. Utilise spray foam or rigid foam insulation, or construct the shaft walls with structural insulated panels (SIPs). If using fiberglass batt insulation, cover it with a rigid material like rigid foam to prevent sagging and create an interior air barrier. Ensure that the skylight shaft walls are insulated to the same R-value as other exterior walls if the attic they pass through is not insulated.

Regularly inspect the skylight shaft for any signs of paint failure, water damage, or leaks. White paint is advantageous in this regard, as it is easy to stain and will make any leaks more noticeable, allowing for prompt repairs.

Finally, consider the aesthetic aspects of the painted skylight shaft. While personal preference plays a role, it is generally advisable to choose a colour that matches the room's wall paint for a unified look. White is a popular choice as it reflects light well, is easy to maintain, and complements various design styles.

Frequently asked questions