
Nicholas Mitchell
Hi Suzanneu. The brick at the top will have cracked because unlike the lower bricks its not surrounded & packed in. Try fixing vertical battens first, 2 or 3 will be enough. Cut the vertical timber to the top of the wall & fix no higher than 3 bricks from the top. You can put as many fixings into the vertical pieces but 5 should be enough for each one. Put 1 fixing in the 3rd, 5th & 7th brick down from the top & the final 2 a bit more lower down. Then screw a horizontal piece to the top of the vertical pieces & fix your pull up bar to this. Doing it this way will help to spread any force against the brickwork. If you only screw a horizontal batten to the top there is a good chance it will keep coming off, you'll keep cracking the brickwork, it may pull the brickwork out. Hope that helps Nick