Why does pressure treated wood crack

This is bound to happen with such extreme conditions with the cold winter and the very warm dry heat of the wood stove. My bet is they will close up and be invisible again in a few months.

I highly doubt you have any structural loss. Thanks for this information, I am doing one project where I am supplying Red Meranti Wood from Malaysia in two different sizes… mm x 76mm and mm x 63mm which is for Door Frame. We assembled the frame and handed over to Client, now their Quality person observes cracks on the surface and rejected.

Please advice me what I should explain him for this…. At that thickness the interior of those boards would have been even higher in moisture content so the outer parts of the board are drying out faster than the interior and the expansion cracks are opening up.

They will mostly likely go away over time but no one will guarantee this to happen. What about a crack in horizontal cross beam of front porch? It supports the roof line overhang of porch.

I live in dry hot western climate with rain thru winter. Is this a safety issue? House was built in the late 40s. Hard to say with certainty as there are so many variables but I suspect the crack is exactly as described in the article: just differential drying that is relieving stress and should make for a more stable beam. The lower portion of the beam is not laterally braced.

The beam also has post from the roof above, residing on it, that are aligned with the lower support beams.

The beam is supported by a threaded screw between the posts and the beam that essentially creates a hinge point verses solid bearing. The beam has a large check but of more of a concern is that the lower portion of the beam below the check is twisting outward away from the joist side, as much as 1. Appreciate your opinion about the beam-is the lateral movement a failure concern? Bill, I would definitely consult with an engineer on this one.

You have a lot more going on with multiple tie in points and force vectors. I have a beam its I guess supporting my home??? They chew their way in regardless.

Shannon, I listen to you on wood talk and love the wood reports you give. I build furniture so I understand wood movement. Recently built an addition to the house with a flat roof. I have four 8 inch rough cedar beams extending through the roof into my shop below. And I will be adding an arbor with the beams supporting it. The beams have been in place for about 10 months and some have checks the entire distance vertically. I plan on installing metal caps on the exposed tops but am concerned that when it rains water could get into the vertical cracks and run down into my shop.

Do I just live with it or is there something I can do to prevent that? So the beams are exposed to the elements above? I think your concern is valid which is why additional roofing work should probably be done. Having the water run all the way through the beam would actually be preferred to have it pool and stand inside the crack where it can accelerate decay in the beam itself.

Is there any concern over structural integrity with the roof posts? As stated in the article in many ways those cracks release the tension in the wood and make it more stable.

This depends on the look you want but when it comes to exteriors I prefer an oil. An oil finish will soak in and provide some protection to the elements but also help to slow the moisture exchange that can cause large cracks to open in the posts. It will require additional maintenance annually or bi-annually but so would any finish.

A film finish like a varnish however will need to be stripped away before a fresh coat is applied whereas an oil need only be reapplied. I have a porch with cedar beams horizontally and vertically.

I saw a previous comment about using oil as opposed to stain. They are already stained but will need more care in a year or two. What kind of oil do you recommend? Stain is a mixture of pigment in solution where the solution whether oil or water based evaporates away leaving behind the color pigment. What should I do to remedy this?

Would power washing help or just produce the same result? Or should I replace the problem boards altogether? Should the warranty on pressure-treated boards cover this? Treated lumber is injected with chemicals that are mixed with water. When the sun bakes this moisture out of the lumber, it creates significant tension stress within the wood fibers. Tension is the force that happens when you try to stretch or bend something.

As the sun cooks out the water, the lumber shrinks. This shrinkage usually causes tiny checking cracks to form. In extreme cases you can experience delamination along the boundaries of the summerwood and springwood. Summerwood is the dark ring you see in a log, and the springwood is the lighter-colored band. When this delamination happens on flat-grained pieces of lumber, you end up with giant protruding splinters like I see in the photo you sent.

However, one significant downside to these composite boards is their cost. Years ago, one of the chemicals used on pressure treated wood was arsenic which is obviously very dangerous. However, a new law was passed in that prevented arsenic from being used in pressure treated wood. Many people are unaware of the law and still assume that arsenic is still being used in PT wood and therefore believe that pressure treated wood is not safe for them to have around their children. If your child gets exposed to wood that was produced prior to , there is certainly a risk of arsenic exposure.

This is especially true if they have potentially consumed or been around pressure treated wood that was made before when arsenic was used. If you are concerned about exposure to any of the chemicals, please call the National Poison Hotline at Symptoms of arsenic exposure can include: vomiting, nausea, varied heart beat and numbness in extremities.

Chemicals used in pressure treated wood after include: copper azole, alkaline copper quaternary or micronized copper azole. Symptoms to prolonged exposure to these include redness of skin and nasal dryness. No, it is not a good idea to burn pressure treated wood. As we mentioned above, there are several chemicals that are used to pressure treat the wood. Wood created before has the risk of containing arsenic.

Anytime you burn something, fumes are released into the air which can be easily inhaled. This is especially true if you were to burn pressure treated wood. Doing so, would put you and anyone near the fire at risk for breathing the toxic fumes. It is illegal in all 50 states to burn pressure treated wood that contains arsenic due to the deadly toxins that would be released. Laws vary by state on how you can dispose of pressure treated wood.

Larger amounts should be taken to your local landfill. You can call them to find out specifically where you can take it. These these boards will be stored in landfills that have liners to prevent the potential for any chemicals leaking into the ground. Yes, pressure treated wood performs very well, even if submerged under water. In fact, most companies will guarantee their pressure treated woods will hold up for at least 25 years when submerged.

Wood that has been submerged underwater behaves a bit different that wood that is kept above ground. Wood that is above ground will expand and contract more due to the variability in moisture, heat, humidity and sunlight that it receives. The conditions under water have a bit less variability. No, it is not suggested that you bury pressure treated wood in concrete. The problem with pouring concrete around pressure treated posts is that water gets trapped and can cause the posts to rot and decay.

The problem with concrete is that over time, it will develop small cracks. However, each time it rains, water will seep down into the cracks and continue to soak into the pressure treated boards. Over time, this will create rot and decay to setup. The best way to use use pressure treated posts in the ground it to pour a concrete footer and add a post anchor to it.

Yes, it is very common for homeowners to use pressure treated wood to hang their mailboxes. However, the most common mistake I see is that homeowners will bury them in concrete. As we covered in the paragraph above, it is never recommended that you bury pressure treated wood into concrete.

Another common wood for people to use are their mailbox post is cedar or redwood posts. These species of wood will work well too, but are typically much more expensive. Pressure treated wood tends to have considerably more knots that cedar and redwood which some people may find unattractive.

Many people are surprised to learn that you should NOT use pressure treated wood around anything made of aluminum. One of the chemicals used to make pressure treated wood is copper.

Aluminum and copper do not mix well together. In fact, the copper will cause the aluminum to corrode over time. The wood will cause the aluminum to corrode on the trailer over time.