How to protect an open-ended pergola from rain?

[MattD2]

 

Hi, we have an existing outdoor pergola (8x12m). Two sides are enclosed by the house and 2 sides are open. 

one gable end is open however the other end which joins the house has been sealed with twin pall Perspex. 

That design has worked well for rain protection but the heat retention in summer, condensation in winter, and airflow year round is terrible. 

I removed the Perspex to test the airflow which now works well, but predictably is terrible for rain protection. 

interested in any ideas. - My thoughts were a series of angled timber slats but maybe weight would be an issue.

Photo is of the end we are looking to improve.

thanks.  

[MitchellMc]

Welcome to the Bunnings Workshop community @MattD2. It's wonderful to have you join us, and many thanks for your question about enclosing a pergola.

I agree that angled timber slats could be an excellent compromise. They should provide airflow while still offering some protection from rain, especially if positioned correctly to shed water.

To give you a visual idea, I’ve created the renderings below. If you experience a lot of driving rain, you might need to make the slats angle more aggressive, though this does diminish airflow. The slats are fixed at their ends and supported by batons, which should help distribute the weight. This design keeps the structure lightweight yet functional. 

That said, any modification that adds load to a roof structure should always be assessed by a professional, such as a builder or engineer, to ensure it's safe and compliant with regulations. They can also help confirm whether the existing roof frame is capable of handling the additional weight.

Please let me know if you have any questions.

Mitchell
 

[MattD2]

That’s amazing, Thanks for taking the effort to draw that up, it’s much easier to visualise it now. 

Mike question if I may- how would you suggest connecting the slats to the batons?