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Hi Community,
We've just had our deck redone and we've noticed a lot of cracks in the merbau where the screws are. Our carpenter has completed about 95% of the screws and there are about 100 cracked areas on our 60m2 deck. He's been using these screws, which do not require a pilot hole, as long as you're far enough away from the edge and ends of the boards, I believe:
- Simpson Strong-Tie 12G (5.5mm) x 65mm 316 Stainless Steel DHSD No-PreDrill Hardwood To Softwood Decking Screws
He's advised us that he hasn't been drilling pilot holes when in the middle of the boards, but has been on the ends of the boards with a regular drill bit the same size as the screws, but not a countersinking drill bit.
The decking is pre-oiled 90x19mm merbau.
He will likely replace the worst of the boards, but with about 100 cracks, we won't be able to get everything.
Reaching out to see if there's anything we can do with the cracked boards that are left. Currently planning to wash, oil and maintain regularly, but also considering trying to seal cracks with Selleys Aquadhere PVA Wood Glue Exterior Adhesive, removing adjacent screws, wedging boards closed, re drilling screw holes and then screwing again. To try to seal up the cracks as much as possible.
Any advice would be greatly appreciated.
We understand that predrilling all screws with a countersinking drill bit 15-25mm from the edges and ends of the boards is best practice and how to avoid this happening, but the deck is almost finished now and we're looking for a solution moving forward.
The wedges in the photos are marking some of the cracked areas.
David
Hi @David10
I showed these photos to a registered builder mate of mine and he confirmed the main issue is that the screws have been installed to close to the edge, which puts the issue back on the installer to make good.
If it's going to be an issue, a compromise could be to lift the damage boards, and cut the affected area and refit. Then fill the gaps with infill boards as long as they aren't too short for aesthetics. There are also unacceptable gaps between some boards which isn't acceptable in a professional built deck as per the photo below. Again back on the installer.
I know this puts you in an uncomfortable position between yourself and the installer, but you have paid what I would imagine a large sum for this deck and there shouldn't be any issues like these.
Nailbag
Hi everyone,
Thanks very much for your help on my last post. Our carpenter has fixed up a few of the worst areas, but we still have some concerns. The deck is looking nice at first glance, as you can see from the first photo, just some of the finer details are a bit rough/potentially need some more work.
1. Our carpenter used the below decking screws which are not supposed to require a pilot hole, however they've left about 100 cracks in the boards. The consensus has been that many of the screws are too close to the edge of the boards and he should have switched to drilling countersunk pilot holes when they started cracking. He's now doing this when replacing boards.
- Simpson Strong-Tie 12G (5.5mm) x 65mm 316 Stainless Steel DHSD No-PreDrill Hardwood To Softwood Decking Screws
Our decision now is what to do with the cracks. We could ask the installer to supply and replace all the cracked boards, but that's about 20m2 of decking and most of the cracks are very fine. Is this an issue long term? We've been advised that the cracks will become more noticeable over time, especially after oiling as the oil will sit in the cracks. Or we can just leave the cracks and live with it. Will they rot faster, as water sits in the cracks?
The wedges in the first photo are marking cracks on half the deck.
2. We feel the end decking board at this step could be finished better, but we're not sure. At the moment it's bent down on both sides to slide under the existing stair stringers, however can't some of the stair stringers be shaved off to give the decking board more room? If so, what tool would be best to use? It would need to fit in that gap and leave a neat finish.
There's also a join on the left side, when it looks like one board could have been used. Use a longer board, slide it under one side, lay it down and then bring it under the other. is this straightforward to do?
3. Quite a few very rough screw holes. These occurred when using the countersinking drill bit with the depth stop removed. The installer removed the depth stop in some areas under the existing hand rail where he couldn't use it, but didn't put it back on when he moved back to unrestricted areas where it could be used. Most of these rough screw holes are not in obvious areas like under the handrail.
- P&N Quickbit Smart Countersink Drill Bit
Do we just need to take to these with a bit of sandpaper, or are they more difficult to tidy up?
4. When our installer switched to using the countersinking drill bit with the depth stop removed, some of the holes were quite deep. Our concern is water will sit in these holes and reduce the deck's lifespan. Should these boards be replaced? We live in a very wet area of Victoria.
5. Can this rough edge be fixed up with sandpaper?
6. What tool could we use to take off some of the bottom of this existing post to bring the decking board up level with the rest? Is that appropriate to do?
7. Should we replace this board or will this mark fade over time? It doesn't bother us too much, just more wanting to know what's usually done.
Any advice would be greatly appreciated.
David
Afternoon @David10
Thats a few questions 
lets see if Ican go through them.
Q - Our decision now is what to do with the cracks. We could ask the installer to supply and replace all the cracked boards, but that's about 20m2 of decking and most of the cracks are very fine. Is this an issue long term? We've been advised that the cracks will become more noticeable over time, especially after oiling as the oil will sit in the cracks. Or we can just leave the cracks and live with it. Will they rot faster, as water sits in the cracks?
A - Your installer should be replacing the cracked boards at their cost. Especially once they cracked while installing and then continuing the install. All that goes through my head is a bair foot dragging across the floorboards and swick....... followed by a scream 😕 floorboards need to be free of slivers.
1- We feel the end decking board at this step could be finished better, but we're not sure. At the moment it's bent down on both sides to slide under the existing stair stringers, however can't some of the stair stringers be shaved off to give the decking board more room? If so, what tool would be best to use? It would need to fit in that gap and leave a neat finish.
1a - The more I look at your photos the more I think the weight of the steps are resting on that floorboard and not really supported. The boq in the timber really heads my mind towards this. I would suggest to investigate how the steps are attache dto the edge of the deck, working backwards from there you should be able to see what is missing and how those two "arms" should be resting.
2 - There's also a join on the left side, when it looks like one board could have been used. Use a longer board, slide it under one side, lay it down and then bring it under the other. is this straightforward to do?
2a - I would say its not a simple thing to do as all the weight seems to be resting on the top board and not the side. The steps should have been supported / lifted even when the board was installed. They seem to have taken a short cut?
3 - Quite a few very rough screw holes. These occurred when using the countersinking drill bit with the depth stop removed. The installer removed the depth stop in some areas under the existing hand rail where he couldn't use it, but didn't put it back on when he moved back to unrestricted areas where it could be used. Most of these rough screw holes are not in obvious areas like under the handrail.
- P&N Quickbit Smart Countersink Drill Bit
Do we just need to take to these with a bit of sandpaper, or are they more difficult to tidy up?
3a - These are an easy fix, You could use a large drill bit and dusing your hand just twist the drill over the hole, it will champher off any of the left over strands of timber. You could also use a wide chisel gently, just rid ethe chisel over the area with the flat part of the blade facing down. Dont push too hard a syou dont want to add scratches to the boards.
4. When our installer switched to using the countersinking drill bit with the depth stop removed, some of the holes were quite deep. Our concern is water will sit in these holes and reduce the deck's lifespan. Should these boards be replaced? We live in a very wet area of Victoria.
4a - This one is a personal preference Ithink. I have done some too deep countersunk holes on my deck and have had no issues in ten years. The deck is open and also next to the pool. I have also just done a timber top to a gabion wall and steps that are very much like the picture. I figure they will drain ok and used more oiling when I oiled. You could also put timber plugs in them if concerned. Using a hole saw cut out the same dimension as your existing holes, then insert them into the hole using glue. once dry use a chisel to tap off the excess.
5. Can this rough edge be fixed up with sandpaper?
5a - Yes it can be but id suggest to use a file to smooth first as its quiet rough. Sandpaper will just take longer.
6. What tool could we use to take off some of the bottom of this existing post to bring the decking board up level with the rest? Is that appropriate to do?
6a - I would be reluctant to do chop off any of the existing post, A multi tool is what i would use if you went that way. The installers should have smoothed the dip out when installing the boards. One of the supports probtally has dropped some.
NOTE - the previous photo for this question looks like it has rotted timber. have you accessed the underlying timbers and posts for any rot?
7. Should we replace this board or will this mark fade over time? It doesn't bother us too much, just more wanting to know what's usually done.
7a - I wouldnt replace the board, the spot may fade with time. You could scrub with a course brush and soapy water or even sand it a little if it is still there afterwards. Decking has its own indervidual marks, just depends on how much it catches your eyes.
For all the imperfections that you have raised my first step woyuld be to get the installer back and go through them all (as a list) and decide upon what can be done and what can be lived with. They have installed it and it needs to be safe (the splits in the timber) The licence they have and fair trading would be something I would get as well.
Dave
Hi @Dave-1,
Thanks very much for your detailed reply.
As you can see in the photos, some of the cracks are very small. If our installer refused to replace them, are even these small cracks likely to cause issues? We may have to decide whether to pay someone else to supply and replace these boards or live with them.
1. The steps were left in place and used while the deck was being redone and I don't think the deck is providing much if any support. See photos. I think most of the force is going into the side of the old cladding (not sure if that's the right term) and into a stump behind.
2. I believe the existing handrail is nailed to the existing posts, so dismantling it may have been difficult when redoing the deck. Our installer said he didn't want to cut the stair stringer as it wouldn't have been a clean finish, so bending the board down to fit under was his solution. But it seems like with the right tool, the stringer can be cut where it meets the new deck, to allow the deck to be level and not bent down. I'm just not sure what the appropriate tool is. Reciprocating saw? Multitool?
4. Good to know. The deep holes do seem to eventually drain.
6. We assessed for rot before redoing the deck. The existing decking and joists were the worst, but the handrail and posts weren't too bad. Some superficial rot. We'll replace the handrail and posts later if needed.
We'll be getting the installers back soon to go through everything, I just needed to get my head around a few things first. As i mentioned, some of the splits in the timber are very small, and we're not sure how much to ask them to replace. Obviously if they're large, visible and possibly dangerous they'll be replaced, but some are very small, maybe less than 0.5mm width and 20mm long. Should these all be replaced? During an earlier conversation with our installer when I first noticed the cracks he mentioned that cracks on the end of the boards is common, but not in the middle, and also crack defects only need to be addressed if they're visible from more than 1.5m or so. Is this valid or is he just trying to avoid responsibility?
For reference the boards are 90mm wide. I tried to take a variety of crack photos in my post yesterday, showing large and small ones.
David
Good Evening @David10
With the splits in the timber it really is going to come down to how you feel about the decking. You could have 10 differant opinions on what to do but its your deck so better to go with some kind of cut off point (say certain splits are a no while others are so so)
The tool you are after is a multitool, they look very handy and ive only used one once but its on my list
The steps and how they are resting, another one that is up to you, leave as is for the time being and then plan to do something if it becomes a problem?
Its good that you assesed the timbers, makes it a non stress process down the track.
As to cracks being common, id say nope. Ive never heard of that before and no one has mentioned it in the posts I have seen in here unless there was a problem. You could ask for photos of examples elsewhere but it would be better to balance between getting it fixed at their cost and a going down the route of a complaint. Hard call but something that could save you more hassel.
Dave
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