This study conducted with French-speaking students living near Montréal, Canada, assess if teaching the shared knowledge between reading and writing of informative texts improves reading comprehension in fourth grade (9-10 years old) to a greater extent than teaching that separates reading and writing. Teachers participating in the experiment received teaching material and training during 1 year prior to data collection. The teaching approach involved three steps and included activities that were spread over 20 weeks and lasted approximately 2 h per week. Teachers from the non-experimental condition teach reading comprehension and writing strategies in a dissociated way. Students (n = 248) were tested with a reading comprehension assessment in September and May. Results show a significant interaction between time and groups, suggesting a moderate effect size. The experimental group started the experiment slightly behind in reading comprehension and ended up significantly better than the control group. Teaching how to articulate knowledge in reading and writing might favor reading comprehension of informative texts better than teaching strategies in a dissociated way. However, the introduction of such an approach required continuous training and robust teacher support.