We are building an extension and removing the back wall (bedroom & bathroom above). We have structural engineer drawings and have the beams as specified. The opening is 5.1m long. The wall is a cavity wall & the joists sits on the cavity wall. We are holding up the floor above with scaffold boards & acrows, alll sitting on solid floor. Will strongboys suffice on the outher wall ? We have placed them approx. 800mm apart, 6 in total for the 5.1m span. They are all in place, but we have not yet taken out the wall. Any advice/ reassurance about the strongboys / acrows would be appreciated, My concerns are if the strongboys will suffice due to the span of the opening - thank you