grip fill a couple of peices of board on the botton but measure the width wider than the lintel but only as wide as the wall is, use a wooden dead man to hold in place if you need to.
once its dried some bonding with mesh bedden into it makeing sure not to bring this coat up to level then once thats gone firm but not dry a second coat of bonding to flush if your skimmng the whole wall of just below flush if your just patch repairing the area
gripfill will probably only be sticking to the paint unless you can get plenty to squeeze throught the holes and slump. nog out the sides and notch the bottom so it hangs5-10mm bellow the bottom of the lintel, then cut your board for the bottom, plenty of drywall adhesive push up hard so it squeezes through the holes and fix onto the noggins using 38mm screws.
then just fix board to both sides of the catnic to the noggins, job done
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local