How to kill weeds under low-level deck?

[etak1]

We  just had a professional instal a 10 metre x 2 metre decking last month.  Already a big weed is starting to grow through.  Looks like the weed mat he lay down wasn't properly secured at the end and most probably there was no extra little bit of  mat up the side of the wall (also, he didn't put any crushed stone to put on top of it to hold it down).  Now a weed is already growing up the side to the deck.  What should I do?  It is a low deck.... touching the ground so I can't get under and there's a concrete slab directly at the side.  

[JacobZ]

Hi @etak1,

Thank you for your question about managing weeds underneath your new deck.

My suggestion is to remove a board, so you have access underneath to remove the weed and add some drainage gravel over the weed mat to hold it in place.

You can see the screw in the top right corner of the photo that is fixing the board against the brick in place. These screws have a torx head. I couldn't say what size from the photos, but this Trojan 15 Piece Torx Screwdriver & Bit Set has all the likely sizes. You can use this to remove the screws and lift this board.

Once lifted, you can manually remove any weeds and then use some drainage gravel to hold the weed matting in place against the wall and to help suppress the weeds.

You can then reinstate the board using the same screws and holes to fix everything in place.

Let me know if you have any further questions.

Jacob

[etak1]

Thank you so much for your help Jacob. 

[JacobZ]

No worries @etak1.

Let me know if you run into any issues.

I'm happy to assist further if required.

Jacob