I haven't heard anything from the school yet, as to whether they'll be closed, but I assume they'll be affected, as the largest union taking part etc.
That week they're running overnight trips for Y3. There are 3 classes in the year group and each class is to spend one night and the following day at a local Scout campsite. 2 staff are staying all week and the class teachers and support staff are to go with their own classes.
DS2's turn is the night before and the day of the strike. What will they do?
Suggest you ask school or wait for their announcement - they may or may not have staff who intend to participate in the strike. School will be trying to ascertain what staff they need to cover. I imagine they will do all they can to avoid disappointing the children - don't you?.
It will depend if the teachers involved in the trip are eligible members of the striking unions. If they are NASUWT/NAHT/some other non-striking union it shouldn't make a difference. Union members who are involved in trips, proms, public examinations etc. can apply, through their union rep. for an 'exemption' so it may be that your son's teachers have done/will do that.
In primary schools some classes will be at school and not others depending on which union the individual class teachers are in - no one is allowed to do their jobs whilst they strike. Secondary schools are a bit harder to organise and I imagine lots will be fully closed if they have a lot of striking teachers.
In DC's school it is the year 6 residential that week. There is also a sports event planned for year 3 and 4 that afternoon. DC in reception and year 2 so wouldn't be affected by either but am interested in what will happen.