How do I stop rain coming in the side of my pergola?

The Problem

Rain getting into the sides of a pergola can be a frustrating issue for homeowners. There are a few potential causes of this problem:

• Gaps between pergola roofing boards allowing rain to drip through
• Runoff dripping down pergola posts onto the sides
• Wind-driven rain blowing in from the sides

The extent of the issue will depend on factors like how heavy the rain is, the direction it’s coming from, and how well-sealed the pergola is overall. But even a small amount of rain getting in can lead to annoying drips and leaks. Thankfully, there are solutions for stopping rain coming in from the sides of your pergola.

Assess Where the Rain is Getting In

The first step is to observe where exactly the rain is entering from. This will help determine the best approach to tackle the problem:

• If it’s mainly dripping between roof boards, sealing gaps will help.
• If runoff is coming down posts, directing that water away is key.
• If wind-driven rain is blowing in, blocking the sides may be needed.

Go out during a mild to moderate rainfall and watch for drips and leaks forming along the sides. Also check under the pergola for any signs of water ingress. This inspection will reveal the main source(s) of the issue.

Seal Gaps Between Roof Boards

One common way rain sneaks into a pergola is by dripping between gaps in the roof boards. Over time, wood can shrink or warp leading to small cracks opening up. The solution here is to seal these gaps to prevent water getting through.

There are several flexible sealant products made for this exact purpose. Look for an exterior-grade caulk or silicone that claims to be good for sealing wood, gaps, and cracks. Some good options include:

• Silicone caulk
• Polyurethane caulk
• Acrylic latex caulk

Prepare the areas between boards by cleaning out any dirt, debris, old caulk, or peeling paint. Apply the new caulk by running a smooth and continuous bead that completely fills the gaps. Aim to do this on a dry day when no rain is expected for 24 hours so the caulk has time to fully cure.

This sealing should help stop annoying drips from falling through roof gaps. But it’s also important to redirect runoff and block wind-driven rain as well.

Manage Runoff Dripping from Posts

Even if the pergola roof itself is watertight, rainfall can collect on top and then drip down the vertical posts. Once it reaches the posts, gravity takes over sending water down the sides. And this runoff can soak into the pergola enclosure.

There are gutter systems made specifically to catch this roof runoff and divert it away from posts. Essentially they provide a channel that attaches to the edge of the roofline and redirects water into a downspout. The water then drains away keeping it off the sides.

For pergola posts:

• Aluminum wrap-around gutters can be secured to collect roof runoff.
• Self-adhesive foam tubes can catch and divert drips from round posts.
• Covering the tops of posts with decorative caps can prevent water from dripping down.

Proper drainage is crucial so any collected water doesn’t just pool on the ground against the pergola. Make sure downspouts are directed several feet away into landscaping or a storm drainage system. A dry well can also handle runoff dispersal.

Managing this roof runoff will cut down on the amount that makes its way onto the sides. But for heavy wind-driven rain, blocking the sides may also be needed.

Block Sides from Wind-Driven Rain

While sealing the roof and diverting runoff deals with water dripping down, rain can also blow in from the sides in windy conditions. This horizontal wind-driven rain can easily penetrate into a pergola. So deflecting it becomes necessary.

Here are some ways to block rain from blowing in while preserving the open-air nature of a pergola:

• Install clear vinyl weather curtains on the ends and sides. These can be rolled up when not needed.
• Secure acrylic or polycarbonate panels to create a wind barrier while maintaining visibility.
• Grow climbing vines up wires, lattices, or trellis panels attached to the posts and beams.
• Affix weather-resistant fabric drop curtains along the perimeter to diffuse and obstruct sideways rain.

The coverage and durability of these solutions will vary. But they share the goal of impeding wind-driven rain without compromising too much on light and views. Remove or roll up the barriers when not in active use.

Combining gap sealing, runoff diversion, and wind blocking provides multiple layers of protection against rain ingress. Evaluate which aspects are most needed for your pergola situation.

Improve Drainage Around The Pergola

Beyond the pergola itself, it’s a good idea to improve drainage and grading around the structure. This prevents standing water and saturated soil from pressing up against the sides. Recommendations include:

• Grade soil so it slopes at least 1 inch per foot away from the pergola.
• Use landscaping rocks, pebbles, gravel, or pavers to reduce mud and surface puddling.
• Install a French drain along the perimeter to collect ground runoff.
• Extend downspouts several feet away with splash blocks to disperse outflow.

Proper drainage is just as important as sealing and covering. It works hand in hand to reduce problems with water ingress through the sides.

Maintenance to Prevent Future Leaks

After addressing immediate issues, ongoing maintenance helps prevent rain from re-entering your pergola. Check for new cracks and gaps in roof boards each year before rainy season. Re-apply caulk and seals as needed to maintain watertight protection.

Here are some other good periodic maintenance tips:

• Inspect runoff diverters and downspouts to make sure they are clear of debris clogs and working properly.
• Check side panels and curtains for any tears or gaps needing patched.
• Clean out gutters and ensure they are still securely attached without leaks.
• Trim back overgrown vines or branches from roof and side coverings.

Staying on top of repairs and upkeep prevents small issues from becoming big problems over time. And carrying out preventive improvements now can help stop rain from invading your pergola all season.

Summary of How to Stop Rain in Pergola Sides

Dealing with rain coming in the sides of your pergola involves assessing where leaks originate and implementing solutions:

• Sealing gaps – Caulk and fill openings in roof boards so water can’t drip through.
• Managing runoff – Redirect drips from the roof surface away from posts and sides.
• Blocking wind-driven rain – Install side curtains, panels, or plant vines to impede sideways rain.
• Improving drainage – Grade surrounding soil and add elements like gravel or French drains.
• Regular maintenance – Monitor for new gaps or leaks and keep water diverters clear.

Combining these approaches provides layers of protection and keeps the interior of your pergola dry. No more annoying drips or worrying about water damage. And you can enjoy the space without rain ruining the experience.

Your pergola should provide comfort and function. By properly sealing it against precipitation and managing runoff, you can relax under cover and out of the weather. Keep the above tips in mind when planning and maintaining your ideal outdoor living area protected from the elements.

Frequently Asked Questions

What are the main causes of rain getting into pergola sides?

There are three common ways rain can find its way into the sides of a pergola:

• Dripping through gaps in roof boards
• Runoff from the roof flowing down and off pergola posts
• Wind-driven rain being blown in from the sides

Assessing where exactly moisture is entering from will determine the best fixes.

What can I use to seal between roof boards?

Some good sealant options for gaps between pergola roof boards include silicone caulk, polyurethane caulk, exterior-grade acrylic latex caulk, and other flexible waterproof construction caulks.

How do I stop rain runoff soaking my pergola sides?

Manage roof runoff by installing rain gutters to collect water and divert it away from posts into downspouts. Or cover post tops to prevent drips running down. Proper drainage like French drains also keeps ground from being oversaturated.

What can I put along the sides to block wind-driven rain?

Vinyl curtains, clear acrylic/polycarbonate panels, weather-resistant fabric, and climbing vines/plants can all help obstruct side wind-driven rain without fully blocking views and light.

What maintenance tasks help prevent water ingress?

Re-apply caulk seals annually, keep runoff diverters clear of debris, check curtain and panel coverings for tears, clean out gutters, and trim overgrown vines. Catching small issues early prevents major leaks.

Conclusion

Unwanted rain entry on pergola sides can definitely be frustrating. But there are practical solutions for controlling moisture from above, beside, and below. Assess where the water is coming from and implement fixes like caulking, diverting runoff, installing shielding, and improving drainage. Regular maintenance is key as well. Keeping your pergola properly sealed and protected preserves its beauty and function for enjoying the outdoors in any weather.